Rudi I&I Automan
Well-Known Member
http://watercustomers.com/free-water-testing-kit-form.php the company are going to hate me for this one lol
The UK Growers Thread!
- Thread starter lozac123
- Start date
The Yorkshireman
Well-Known Member
Don't even worry about what's in your tap water mate, anything in it is a bonus and there's nowhere near enough in hard water to cause problems.
You could Brita filter your water before using it but that's an expense, filters cost £5 (ish) per 200L, and the jug at like £20 (one off).
The Yorkshireman
Well-Known Member
Just make up your feed the same regardless what's in the water.
The Yorkshireman
Well-Known Member
This is the UK Growers thread, that's a U.S promotion.
.com instead of .co.uk usually gives the game away and it's confirmed when the promo wants a state and zip code in the address.
The Yorkshireman
Well-Known Member
Yeah man, long gone.
bazoomer
Well-Known Member
A good base nute, no mistical boosts ect, keep environment good ,temps , humidity ect & I rekon ya good to go. I always get a decent crop. It's when I start fookin about thinking I'm a pro botanist & adding this & that , things fuck up ! .less is more I've found over the years.
theslipperbandit
Well-Known Member
My water comes out the tap @7ph n a super soft I'm talking less than ten so that's the only bonus to living in ireland...dacent water
Rudi I&I Automan
Well-Known Member
cal/mag are not the only minerals 2 worrie about in tap water
rain water can have disolved salts/chemicals in it and become just as problematic if not more so then hard/soft water,due to industrial polution that can be worse then the calcium carbonate that upsets the EC that leaves less space in the water for your chosen plant food in your nute tank
plants take up the cal carbonate form first in preffrence to the form of cal in the nutes used first and thats wot stop the plants from taking up the better form of calcium from nute feeds/solutions,
in some hard/soft water areas, water companys will add chemicals or run it through zeolite filters that replace it with sodium ions (ion exchange beds/filters utilizing differant mediums) leaving a higher concentration of the salt depending on wots used and wot it is exchanged with in the process, same as home water filters work leaving a high sodium content that just poisons the solution and damages or can kill the roots. I found some info that may help, apollogies if some of the info has been posted b4, but if i had to read every post, they would have to bury me with the computer and one hell of a strong wifi conection lol and theres lots to read, i hope its of some use and theres more to come.
how do I manage EC
Since going digital, the number of subscribers to the magazine has increased greatly. We have noticed that there has also been an increasing interest in the fundamentals of hydroponics, for example, the most popular item is now my answer to ‘How do I manage acid addition and pH rise’. Consequently, I will concentrate for the next few issues on covering some of the fundamentals of hydroponics, starting with how to manage EC.
Answer
Background
When a mineral fertiliser, such as potassium nitrate, is dissolved in water it splits into two changed entities called ions. One of these has a positive charge, called a cation, in this case potassium ion, symbol K+. The other has a negative charge, called an anion, in this case nitrate ion, symbol NO3-. Similarly, other fertilisers in solution also split into anions and cations.
The electrical strength of ionic fertiliser solutions can be detected by an electrical conductivity (EC) meter. The higher the ionic concentration, the higher the level of EC, hence EC can be used as an indicator of solution strength.
Units of EC
Unfortunately, there are a number of different terms and units used.
Within most of the international hydroponic community, the standard terminology is electrical conductivity or EC. The standard units are milliSiemens per centimetre, symbol mS/cm. A typical value for a hydroponic nutrient solution would be around 2.0 mS/cm. This is the unit we use in this magazine. Sometimes used is the unit microSiemens/cm, symbol µS/cm, which is one thousand times greater, that is 2000 µS/cm.
The scientists use the same term, but use the units deciSiemens/metre (dS/m), which has the same value as mS/cm. That is, the same solution would be 2.0 dS/m.
There is another term called Conductivity Factor (CF), which started in England, but is now mainly used in New Zealand and by some in Australia. It has no units and is 10 times the value of the EC, hence the same solution would have a CF of 20. I guess that it came from trying to avoid working with a decimal point.
Total dissolved solids (TDS)
At first glance it would make sense to measure the strength of a nutrient solution as total dissolved solids, probably expressed as parts per million. In theory, this is absolutely correct, however, there are major practical difficulties. To analyse directly for TDS is difficult and prohibitively expensive, consequently an indirect method is used.
This is to use a meter which indicates TDS. Apparently very simple, but in practice it is not. The meter used is actually an EC meter and there is an internal correction factor which converts the EC to the TDS readout. Unfortunately, this is where it comes unstuck. Different meters have different correction factors, usually dependant upon the industry in which they are principally used.
For example, for salt water a factor of 500 ppm per mS/cm is used. Other meters use 700 or 750 ppm per mS/cm. Some textbooks quote a conversion factor of 654 for hydroponic solutions, but this only applies to a specific balance of nutrients. Change the nutrient balance and the factor changes.
Consequently, I strongly recommend that growers use an EC meter and avoid using TDS meters.
Limitations of EC
It is important to recognise that while EC gives a good indication of the strength of a nutrient solution, it has its limitations. The first is that the EC gives absolutely no indication of the nutrient balance of that solution. The second is that it does not measure any non-ionic components in the solution. This means that when using organic fertilisers, the solution strength will be higher than indicated by its EC, because most carbon-based compounds are not ionic and won’t register on an EC meter.
EC changes within a system
When a nutrient solution is used in a hydroponic system growing plants, whether recirculating or not, its EC will change with time. This is because there is almost always a difference in the uptake rate of water and nutrients by the plants. Typically, if using an initial solution strength of say 2.0 mS/cm, especially in warm weather, the plants will usually take up more water than nutrient. This extra water is evaporated by the plant to keep itself cool, a process known as transpiration. The end result is that any solution remaining will get stronger and hence have a higher EC.
EC management
The most fundamental aspect of managing a hydroponic system is to manage the solution around the root zone of the plants.
Many growers, especially beginners, tend to concentrate exclusively on their feed solution, but this is only important in terms of controlling the root zone solution. The root zone solution will always have a different nutrient balance to the feed and usually a different EC and pH.
‘Closed’ (recirculating) systems
Typical are recirculating channel and ‘flood & drain’ systems. If you have automatic EC and pH control, then these are obviously controlled. What is not controlled is the nutrient balance of the recirculating solution, especially if there is significant acid addition.
Without a controller, the EC of the recirculating solution will usually rise with time as mentioned earlier. How quickly this happens depends upon the size of your plants, the climatic conditions, and especially the volume of solution you have in the system – the smaller the volume, the quicker the change. If the EC gets too high, the plants will suffer and eventually die.
To prevent this happening and especially if you don’t have an EC meter, it is much safer to have water make-up in your system. In this case, as fertiliser is taken up by the plants the EC will fall. A low EC will give soft plants, but they will survive.
‘Open’ (free drainage) systems
These are dripper fed, media-based systems, where a small proportion of the feed is run off from each container. It is critical to measure the pH and EC of this run-off solution, because this is what you need to control.
As with closed systems, the EC will usually rise through the system, and how far it changes depends upon the same factors, that is, size of plants, etc. Here also, if the EC gets too high the plants will die.
The controls that you have are the EC of the feed solution and the proportion of run-off. That is, if the run-off EC is too high, you can lower the EC of the feed and/or increase the proportion of run-off by increasing the volume and/or frequency of irrigation. Ω
Rudi I&I Automan
Well-Known Member
http://scienceinhydroponics.com/ this may help someone
and the following may help with the ec meter, these are from differant sites.
Ok guys I've decided to write this tutorial on the correct use of EC meters in hydroponics.
I know from reading diaries/posts on here that it is a subject that comes up regularly so hopefully this will address most of the issues.
Let's start at the beginning, EC refers to the electrical conductivity of an object, in our case the EC of our hydro reservoir.
The EC is a measure of the nutrient solutions ability to conduct electricity which is useful because it depends on the amount of nutes so more nutes means higher EC and vice versa.
Much of the confusion surrounding EC is caused because there are three different units of measurement that are used
1 )siemens per meter s/m or sm-1
2 )parts per million ppm
3 )total dissolved solids tds
The last two units are defunct and soon to be assigned to the dustbin of history while the first is the internationally recognized unit adopted by the scientific community so I will only be dealing with that.
OK as we have seen the basic unit of EC is the siemen per meter, i.e. it's ability to conduct electricity over a known distance.
Now that is all fine and dandy but for our purposes it can be a bit unwieldy because we are measuring very, very small readings.
For example if I go and take a reading from my res just now my digital EC meter might say
"123" with a small "x10" symbol flashing in the corner. So what does that mean?
Well first off you have to be aware that most hydro EC meters are calibrated to give readings in micro siemens per meter (us/m or usm-1) not siemens per meter.
This is shown by a "us" symbol above the display and most digital hydro EC meters will have this symbol.
So in this example my meter is telling me I have a EC of 123x10 micro siemens per meter or 1230 us/m.
OK great I have a reading from my meter in units I understand so how does this relate to my grow?
If you are a hydro grower then you will be familiar with feeding schedules like the one I use for my canna aqua nutes.
Pay attrention to the recommended EC levels on the right hand column of these table.
You'll see numbers like 1.2-1.4 so you probably wonder how that relates to my previous reading of 1230 us/m?
If you look closely at the bottom of the table you'll see that recommended maximum EC is given as 2.8ms/cm or 2.8 milli siemens per centimeter so what does this mean?
This tells me that all EC values in the table are given in milli siemens and not micro siemens so we have to take that into account.
2.8ms/cm =2.8 x10-3 siemens per centimeter = 0.0028 siemens per centimeter, done by moving the decimal point 3 places to the left as indicated by the "milli" prefix.
Another thing to notice is the move away from siemens per meter to siemens per centimeter but this doesn't matter because the measurement is still taken over a known distance and this is already dialled into you EC meter so don't worry about it just concentrate on the siemens value.
Basically the move away from siemens to milli siemens is done merely for convenience, it's easier to write 2.8 ms than 0.0028 s.
So basically what we want to do is convert our meter reading in micro siemens into the more commonly used milli siemens. How do we do that.
OK back to the example.
I have a reading of 1230 us that I want to express in ms.
1230 micro siemens = 1230 millionths of a siemen = 1230x10-6 = 0.001230 siemens done by moving the decimal point six places to the left as indicated by the micro prefix.
0.001230 siemens = 1.230 milli siemens done by moving the decimal point 3 places to the right.
So now I have my answer in terms I can work with, my EC is 1.23 milli siemens.
So that is what all the maths boils down to in the end, you will be converting from micro siemens to milli siemens to tie in your readings with the feeding guides and all you have to do is move the decimal point 3 places to the left.
for example
1)meter reading = 500 = 0.5 milli siemens
2)meter reading = 100 x10 = 1000 micro siemens = 1.0 milli siemen
3)meter reading = 190 x10 = 1900 micro siemens = 1.9 milli siemen
Here is a useful online converter you migh find useful
http://www.translatorscafe.com/cafe/...mens-%5BmS%5D/
Online Unit Converters • Electrical Engineering • Electrical Conductance • Compact Calculator
www.translatorscafe.com
Electrical Conductance measurement compact unit conversion calculator.
and the following may help with the ec meter, these are from differant sites.
Ok guys I've decided to write this tutorial on the correct use of EC meters in hydroponics.
I know from reading diaries/posts on here that it is a subject that comes up regularly so hopefully this will address most of the issues.
Let's start at the beginning, EC refers to the electrical conductivity of an object, in our case the EC of our hydro reservoir.
The EC is a measure of the nutrient solutions ability to conduct electricity which is useful because it depends on the amount of nutes so more nutes means higher EC and vice versa.
Much of the confusion surrounding EC is caused because there are three different units of measurement that are used
1 )siemens per meter s/m or sm-1
2 )parts per million ppm
3 )total dissolved solids tds
The last two units are defunct and soon to be assigned to the dustbin of history while the first is the internationally recognized unit adopted by the scientific community so I will only be dealing with that.
OK as we have seen the basic unit of EC is the siemen per meter, i.e. it's ability to conduct electricity over a known distance.
Now that is all fine and dandy but for our purposes it can be a bit unwieldy because we are measuring very, very small readings.
For example if I go and take a reading from my res just now my digital EC meter might say
"123" with a small "x10" symbol flashing in the corner. So what does that mean?
Well first off you have to be aware that most hydro EC meters are calibrated to give readings in micro siemens per meter (us/m or usm-1) not siemens per meter.
This is shown by a "us" symbol above the display and most digital hydro EC meters will have this symbol.
So in this example my meter is telling me I have a EC of 123x10 micro siemens per meter or 1230 us/m.
OK great I have a reading from my meter in units I understand so how does this relate to my grow?
If you are a hydro grower then you will be familiar with feeding schedules like the one I use for my canna aqua nutes.
Pay attrention to the recommended EC levels on the right hand column of these table.
You'll see numbers like 1.2-1.4 so you probably wonder how that relates to my previous reading of 1230 us/m?
If you look closely at the bottom of the table you'll see that recommended maximum EC is given as 2.8ms/cm or 2.8 milli siemens per centimeter so what does this mean?
This tells me that all EC values in the table are given in milli siemens and not micro siemens so we have to take that into account.
2.8ms/cm =2.8 x10-3 siemens per centimeter = 0.0028 siemens per centimeter, done by moving the decimal point 3 places to the left as indicated by the "milli" prefix.
Another thing to notice is the move away from siemens per meter to siemens per centimeter but this doesn't matter because the measurement is still taken over a known distance and this is already dialled into you EC meter so don't worry about it just concentrate on the siemens value.
Basically the move away from siemens to milli siemens is done merely for convenience, it's easier to write 2.8 ms than 0.0028 s.
So basically what we want to do is convert our meter reading in micro siemens into the more commonly used milli siemens. How do we do that.
OK back to the example.
I have a reading of 1230 us that I want to express in ms.
1230 micro siemens = 1230 millionths of a siemen = 1230x10-6 = 0.001230 siemens done by moving the decimal point six places to the left as indicated by the micro prefix.
0.001230 siemens = 1.230 milli siemens done by moving the decimal point 3 places to the right.
So now I have my answer in terms I can work with, my EC is 1.23 milli siemens.
So that is what all the maths boils down to in the end, you will be converting from micro siemens to milli siemens to tie in your readings with the feeding guides and all you have to do is move the decimal point 3 places to the left.
for example
1)meter reading = 500 = 0.5 milli siemens
2)meter reading = 100 x10 = 1000 micro siemens = 1.0 milli siemen
3)meter reading = 190 x10 = 1900 micro siemens = 1.9 milli siemen
Here is a useful online converter you migh find useful
http://www.translatorscafe.com/cafe/...mens-%5BmS%5D/
Online Unit Converters • Electrical Engineering • Electrical Conductance • Compact Calculator
www.translatorscafe.com
Electrical Conductance measurement compact unit conversion calculator.
Rudi I&I Automan
Well-Known Member
Water types, quality and treatments
Good quality water is the foundation of all soilless growing, however not everyone is blessed with a suitable water source for hydroponics. Even crystal clear water may contain a range of minerals, water treatment chemicals and pathogens which can damage plants and cause slow growth. Luckily, water is relatively easy to treat and some growers choose to install small reverse osmosis (RO) units just to ensure their water is always top quality.
By Lynette Morgan, Suntec
Water types and potential problems
Water can be sourced from wells, or collected from roofs, streams, rivers or dams, but many growers are reliant on municipal or city water supplies and while these are usually safe to drink, they can sometimes pose problems for plant growth. The main quality problems encountered with different water types are as follows.
Some water sources can carry plant disease pathogens such as Pythium which cause root browning and death if they take hold of a weakened plant.
Ground water (streams, rivers and dams)
Ground water sourced from rivers, streams or stored in dams/reservoirs typically poses the most problems for soilless growers, particularly if the water is not treated before use. Water which is continually exposed to air and soil becomes contaminated with organic matter, minerals leach from the surrounding area, and pathogen spore loading can be high.
Many greenhouse operations use open air storage dams as an economic method of storingholding large volumes of water collected from greenhouse roofs or other surfaces, however this water is typically filtered and treated before use. River or stream water often has inconsistent water quality as operations being carried out up stream affect composition of the water and rainfall and flow rates also fluctuate throughout the year.
Well water
Water from wells in different locations around the world can vary considerably in quality. Very deep wells passing through certain soil layers will give an almost `filtered water’ although some minerals are always likely to be present in ground water. Some wells, particularly older types, or those which have been poorly maintained and are shallow can present problems with contamination from pathogens, nematodes and agrichemicals leached through the upper soil layers into the well water2.
Well water may be `hard’ and contain levels of dissolved minerals such as calcium and magnesium and other elements depending on the soil type surrounding the well. High levels of sodium and trace elements are the most problematic for hydroponic growers, levels in excess of 2000ppm sodium have been found in inland well waters in some arid regions, although most well waters don’t pose such an extreme problem. Sodium is not taken up by plants to any large extent, hence accumulates in recirculating systems, displacing other elements. Trace elements in ground water, such as copper, boron and zinc may sometimes occur at high levels. Soilless growers utilizing well water are advised to have a complete analysis carried out on their water source to determine if any potential problems exist.
Rain water
Recirculating systems such as NFT can
compound some water problems and
unwanted elements such as sodium
can accumulate over time.
Rain water is generally low in minerals, however acid rain from industrial areas, sodium from coastal sites and high pathogen spore loads from agricultural areas do still occur3. Much of this contamination has been found to happen when rain water falls on roof surfaces and picks up the organic matter, dust and pollutants which naturally collect there. In fact, numerous studies have shown that due to contamination following contact with catchments surfaces, stored rainwater often fails to meet the WHO guideline standards for drinking water especially with respect to microbial contamination3.
In the USA, rainwater collected within 48km of urban centres is not recommended for drinking due to atmospheric pollution3. While drinking water standards don’t necessarily apply to hydroponic growing, the fact that high levels of microbial contamination often occur in stored rainwater means that common plant pathogen spores are also likely to be present. Rain water is best collected from clean surfaces with a ‘first flush’ device installed. which allows the first few minutes of rainfall to be discharged from the roof before any is collected for use.
Rain water may also contain traces of zinc and lead5 from galvanized roof surfaces or where lead flashings and paint may have been used4 and is a greater problem when the pH of the rain water is low. Generally, rain water collected from greenhouse roofs is free of zinc and lead problems.
Hard or soft water
‘Hard’ and ‘soft’ are terms used to describe the quality of many water sources. Hard water has a high mineral content, usually originating from magnesium, calcium carbonate, bicarbonate or calcium sulphate, which can cause hard, white lime scale to form on surfaces and growing equipment. Hard water may also have a high alkalinity and a high pH, meaning that considerably more acid is required to lower the pH in the hydroponic system to ideal levels.
While hard water sources do contain useful minerals (Ca and Mg), these can upset the balance of the nutrient solution and make other ions less available for plant uptake. Smaller growers can counteract this by making use of one of the many ‘hard water’ nutrient products on the market. Soft water, by comparison, is a low mineral water source. Often rainwater is ‘soft’, while municipal water sources across the country range from very hard to soft, depending on where the individual city water supply is taken from.
Other water types
Some growers prefer to start with water which has been pre-treated to remove any chemicals, pathogens and other contaminates. RO (reverse osmosis), distilled water, filtered and bottled water are all options for small growing systems and those concerned with water quality.
City or municipal water supplies
How a particular water source is treated, either before it reaches the grower or afterwards, has a significant effect on its quality. City supplies of water are treated to ensure that the water meets the World Health Organisation standards for mineral, chemical and biological contamination. This means there is quite a wide range of water treatment chemicals which may be added to a city water supply. Many are for pathogen control however hard water may also be treated with 'water softener’ chemicals, acidic water may have pH adjustment, fluoride may be added and other chemicals used to remove organic matter.
These aim to produce a water which is safe for drinking, won’t corrode pipes, leave lime scale deposits, have an offensive smell or stain and be generally acceptable for human use. However what is safe for people, may not be suitable for plants, particularly those in water culture and recirculating systems with little growing media to act as a buffer.
City and municipal water quality
Many city water sources are perfectly acceptable for soilless growers and hydroponic systems and can be used with no adjustment or treatment. However, the water treatment options used by city water suppliers change over time and with advancing technology. In the past, the main concern was chlorine in city water supplies. Chlorine is a disinfection agent which destroys bacteria and human pathogens, and residual chlorine can be detected by smell in a water source. High levels of chlorine can be toxic to sensitive plants, however chlorine dissipates rapidly into the air and can easily be removed by aerating the water or just letting the water sit or age for a few days before use.
While the chlorination of water supplies was easy to deal with, nowadays, city water treatment plants are moving more towards the use of other methods of treating drinking water. It has been found that some human pathogens were resistant to the action of chlorine, and consequently drinking water regulations were changed and alternative disinfection methods are being used more frequently. These days, water may still be chlorinated, but an increasing number of city water supplies have switched to use of ozone, UV light, chloramines, and chlorine dioxide. While many of these methods present no problem for hydroponics and soilless growers, the use of chloramines and other chemicals by many city water treatment plants can pose a problem for plants where high levels are regularly dosed into water supplies.
Solution culture systems don’t have the
buffering capacity of those using a soilless
substrate so are more prone to problems
with water quality.
Good quality water is the foundation of all soilless growing, however not everyone is blessed with a suitable water source for hydroponics. Even crystal clear water may contain a range of minerals, water treatment chemicals and pathogens which can damage plants and cause slow growth. Luckily, water is relatively easy to treat and some growers choose to install small reverse osmosis (RO) units just to ensure their water is always top quality.
By Lynette Morgan, Suntec
Water types and potential problems
Water can be sourced from wells, or collected from roofs, streams, rivers or dams, but many growers are reliant on municipal or city water supplies and while these are usually safe to drink, they can sometimes pose problems for plant growth. The main quality problems encountered with different water types are as follows.
Some water sources can carry plant disease pathogens such as Pythium which cause root browning and death if they take hold of a weakened plant.
Ground water (streams, rivers and dams)
Ground water sourced from rivers, streams or stored in dams/reservoirs typically poses the most problems for soilless growers, particularly if the water is not treated before use. Water which is continually exposed to air and soil becomes contaminated with organic matter, minerals leach from the surrounding area, and pathogen spore loading can be high.
Many greenhouse operations use open air storage dams as an economic method of storingholding large volumes of water collected from greenhouse roofs or other surfaces, however this water is typically filtered and treated before use. River or stream water often has inconsistent water quality as operations being carried out up stream affect composition of the water and rainfall and flow rates also fluctuate throughout the year.
Well water
Water from wells in different locations around the world can vary considerably in quality. Very deep wells passing through certain soil layers will give an almost `filtered water’ although some minerals are always likely to be present in ground water. Some wells, particularly older types, or those which have been poorly maintained and are shallow can present problems with contamination from pathogens, nematodes and agrichemicals leached through the upper soil layers into the well water2.
Well water may be `hard’ and contain levels of dissolved minerals such as calcium and magnesium and other elements depending on the soil type surrounding the well. High levels of sodium and trace elements are the most problematic for hydroponic growers, levels in excess of 2000ppm sodium have been found in inland well waters in some arid regions, although most well waters don’t pose such an extreme problem. Sodium is not taken up by plants to any large extent, hence accumulates in recirculating systems, displacing other elements. Trace elements in ground water, such as copper, boron and zinc may sometimes occur at high levels. Soilless growers utilizing well water are advised to have a complete analysis carried out on their water source to determine if any potential problems exist.
Rain water
Recirculating systems such as NFT can
compound some water problems and
unwanted elements such as sodium
can accumulate over time.
Rain water is generally low in minerals, however acid rain from industrial areas, sodium from coastal sites and high pathogen spore loads from agricultural areas do still occur3. Much of this contamination has been found to happen when rain water falls on roof surfaces and picks up the organic matter, dust and pollutants which naturally collect there. In fact, numerous studies have shown that due to contamination following contact with catchments surfaces, stored rainwater often fails to meet the WHO guideline standards for drinking water especially with respect to microbial contamination3.
In the USA, rainwater collected within 48km of urban centres is not recommended for drinking due to atmospheric pollution3. While drinking water standards don’t necessarily apply to hydroponic growing, the fact that high levels of microbial contamination often occur in stored rainwater means that common plant pathogen spores are also likely to be present. Rain water is best collected from clean surfaces with a ‘first flush’ device installed. which allows the first few minutes of rainfall to be discharged from the roof before any is collected for use.
Rain water may also contain traces of zinc and lead5 from galvanized roof surfaces or where lead flashings and paint may have been used4 and is a greater problem when the pH of the rain water is low. Generally, rain water collected from greenhouse roofs is free of zinc and lead problems.
Hard or soft water
‘Hard’ and ‘soft’ are terms used to describe the quality of many water sources. Hard water has a high mineral content, usually originating from magnesium, calcium carbonate, bicarbonate or calcium sulphate, which can cause hard, white lime scale to form on surfaces and growing equipment. Hard water may also have a high alkalinity and a high pH, meaning that considerably more acid is required to lower the pH in the hydroponic system to ideal levels.
While hard water sources do contain useful minerals (Ca and Mg), these can upset the balance of the nutrient solution and make other ions less available for plant uptake. Smaller growers can counteract this by making use of one of the many ‘hard water’ nutrient products on the market. Soft water, by comparison, is a low mineral water source. Often rainwater is ‘soft’, while municipal water sources across the country range from very hard to soft, depending on where the individual city water supply is taken from.
Other water types
Some growers prefer to start with water which has been pre-treated to remove any chemicals, pathogens and other contaminates. RO (reverse osmosis), distilled water, filtered and bottled water are all options for small growing systems and those concerned with water quality.
City or municipal water supplies
How a particular water source is treated, either before it reaches the grower or afterwards, has a significant effect on its quality. City supplies of water are treated to ensure that the water meets the World Health Organisation standards for mineral, chemical and biological contamination. This means there is quite a wide range of water treatment chemicals which may be added to a city water supply. Many are for pathogen control however hard water may also be treated with 'water softener’ chemicals, acidic water may have pH adjustment, fluoride may be added and other chemicals used to remove organic matter.
These aim to produce a water which is safe for drinking, won’t corrode pipes, leave lime scale deposits, have an offensive smell or stain and be generally acceptable for human use. However what is safe for people, may not be suitable for plants, particularly those in water culture and recirculating systems with little growing media to act as a buffer.
City and municipal water quality
Many city water sources are perfectly acceptable for soilless growers and hydroponic systems and can be used with no adjustment or treatment. However, the water treatment options used by city water suppliers change over time and with advancing technology. In the past, the main concern was chlorine in city water supplies. Chlorine is a disinfection agent which destroys bacteria and human pathogens, and residual chlorine can be detected by smell in a water source. High levels of chlorine can be toxic to sensitive plants, however chlorine dissipates rapidly into the air and can easily be removed by aerating the water or just letting the water sit or age for a few days before use.
While the chlorination of water supplies was easy to deal with, nowadays, city water treatment plants are moving more towards the use of other methods of treating drinking water. It has been found that some human pathogens were resistant to the action of chlorine, and consequently drinking water regulations were changed and alternative disinfection methods are being used more frequently. These days, water may still be chlorinated, but an increasing number of city water supplies have switched to use of ozone, UV light, chloramines, and chlorine dioxide. While many of these methods present no problem for hydroponics and soilless growers, the use of chloramines and other chemicals by many city water treatment plants can pose a problem for plants where high levels are regularly dosed into water supplies.
Solution culture systems don’t have the
buffering capacity of those using a soilless
substrate so are more prone to problems
with water quality.
Rudi I&I Automan
Well-Known Member
1,
Chloramines are much more persistent than chlorine and take a lot longer to dissipate from treated water, hence they can build up in hydroponic systems and cause plant damage. Damage to plants caused by chloramines in city water supplies is also very difficult to diagnose as it looks similar to the damage caused by many root rot pathogens and growers are often unaware of what is causing the problem. Some plants are also naturally much more sensitive to chloramines than others, so determining levels of toxicity has also been difficult.
One hydroponic research study has estimated that the critical level of chloramines at which lettuce plant growth was significantly inhibited was 0.18 mg Cl/g root fresh weight1. Hydroponic growers who have concerns about the use of chloramines in their city water supply can treat the water with specifically designed activated carbon filters or by using a dechloraminating chemical or water conditioners which are sold by the aquarium trade to treat the water for fish tanks. The chloramine carbon filters must be of the correct type that has a high quality granular activated carbon that allows for the long contact time required for chloramine removal. Growing systems that utilize substrates such as coco are a safer option than soilless culture or recirculating systems where water treatment chemicals are suspected to be a problem. Natural substrates provide a ‘buffering’ capacity in a similar way to soil and can deactivate some of the treatment chemicals contained in the water supply.
Other common water quality problems include the use of ‘water softener’ chemical either by city treatment plants, or in the home – these are often sodium salts which result in problematic sodium levels in the hydroponic nutrient. If sodium levels are too high, either through use of water softener chemicals or naturally occurring in the water supply, RO is the best option for sodium sensitive crops.
Tips and tricks for growers
How do you know if you have a water quality problem?
It can be very difficult to determine if a water quality issue is responsible for any plant growth problems which might be occurring. Many diseases and errors with nutrient management or incorrect environmental conditions will produce symptoms very similar to common water quality problems. Ideally, obtaining a full water analysis is useful for most growers, however detecting other issues such as chemical or microbial contamination is more complex.
The simplest method of determining if water quality is the cause of growth problems is to run a seedling trial – growing sensitive seedlings such as lettuce using RO or distilled water as the ‘control’ or comparison will usually show up any problems originating from the water supply. Keeping all other factors such as nutrients, temperature and light the same between the plants in the different water samples and using a solution culture system will give the most accurate test. Comparing growth in the pure water to the suspected water sample will reveal any problems (if growth problems appear in both seedling treatment water samples, then something other than water quality is to blame). Water quality problems may show as stunted roots which don’t expand downwards, short, brown roots, yellowing of the new leaves, stunted foliage growth, sunken brown spots on the foliage, leaf burn and even plant death.
What to do about suspected microbial contamination
Zoosporic pathogenic fungi such as Pythium and bacteria can survive in and be distributed by water6. Water sources which may not have been treated and may contain disease pathogens such as ground, river or steam water can be relatively easily cleaned up by the grower before use. The safest options are UV, ozone and slow sand filtration as these won’t leave chemical residues which may harm young, sensitive root systems. Small UV treatment and filtration systems such as those used in fish ponds and aquariums are suitable for treating water for hydroponic use and will kill plant pathogens and algae. However these are best used for treating water only, not nutrient solutions as UV can make some nutrients unavailable for plant uptake.
Even clean, clear water may contain a range of minerals, water treatment chemical and pathogens which can damage plant growth.
What to do about other contaminates and treatment chemicals
Activated charcoal (slow) filters are still one of the more reliable and inexpensive ways of removing suspected contaminates from a water supply. Herbicides, pesticides, chlorine, chloramines, and other chemicals are reduced to low levels by suitable activated charcoal filters and these can be used by small and large growers alike. If chlorine alone is a problem, aerating the water for 48 hours by using a small air pump will dissipate this chemical. Using substrate-based systems incorporating a media such as coco fibre will give a greater degree of protection and ‘buffering’ capacity where chemical contaminates are suspected.
Aeration of chlorinated water supplies will cause the chlorine to dissipate, making the water safe to use in hydroponic systems.
What to do about excess minerals
Often it is possible to dilute a water supply which may have a slight excess in certain minerals, particularly trace elements, with a higher quality water source, however for water sources with a high natural salinity reverse osmosis or distillation are the only methods of demineralization. Some crops such as tomatoes are far more tolerant of excess minerals and salinity than others such as lettuce, so this factor should be taken into account.
What to do about ‘hard’ water with a high pH
Hard water is best treated with acid to lower the pH to 6.5 before adding any nutrients to make up the nutrient solution or before using the water to top up a nutrient reservoir. This will reduce the total amount of acid required in the system to keep pH under control. Hard water also contains minerals such as calcium and magnesium, so using a specific ‘hard water’ nutrient formulation or product in recirculating systems (like CANNA Hydro Hard Water) is advised, since these will keep nutrient ratios more in balance and also assist with keeping pH in check.
References
Chloramines are much more persistent than chlorine and take a lot longer to dissipate from treated water, hence they can build up in hydroponic systems and cause plant damage. Damage to plants caused by chloramines in city water supplies is also very difficult to diagnose as it looks similar to the damage caused by many root rot pathogens and growers are often unaware of what is causing the problem. Some plants are also naturally much more sensitive to chloramines than others, so determining levels of toxicity has also been difficult.
One hydroponic research study has estimated that the critical level of chloramines at which lettuce plant growth was significantly inhibited was 0.18 mg Cl/g root fresh weight1. Hydroponic growers who have concerns about the use of chloramines in their city water supply can treat the water with specifically designed activated carbon filters or by using a dechloraminating chemical or water conditioners which are sold by the aquarium trade to treat the water for fish tanks. The chloramine carbon filters must be of the correct type that has a high quality granular activated carbon that allows for the long contact time required for chloramine removal. Growing systems that utilize substrates such as coco are a safer option than soilless culture or recirculating systems where water treatment chemicals are suspected to be a problem. Natural substrates provide a ‘buffering’ capacity in a similar way to soil and can deactivate some of the treatment chemicals contained in the water supply.
Other common water quality problems include the use of ‘water softener’ chemical either by city treatment plants, or in the home – these are often sodium salts which result in problematic sodium levels in the hydroponic nutrient. If sodium levels are too high, either through use of water softener chemicals or naturally occurring in the water supply, RO is the best option for sodium sensitive crops.
Tips and tricks for growers
How do you know if you have a water quality problem?
It can be very difficult to determine if a water quality issue is responsible for any plant growth problems which might be occurring. Many diseases and errors with nutrient management or incorrect environmental conditions will produce symptoms very similar to common water quality problems. Ideally, obtaining a full water analysis is useful for most growers, however detecting other issues such as chemical or microbial contamination is more complex.
The simplest method of determining if water quality is the cause of growth problems is to run a seedling trial – growing sensitive seedlings such as lettuce using RO or distilled water as the ‘control’ or comparison will usually show up any problems originating from the water supply. Keeping all other factors such as nutrients, temperature and light the same between the plants in the different water samples and using a solution culture system will give the most accurate test. Comparing growth in the pure water to the suspected water sample will reveal any problems (if growth problems appear in both seedling treatment water samples, then something other than water quality is to blame). Water quality problems may show as stunted roots which don’t expand downwards, short, brown roots, yellowing of the new leaves, stunted foliage growth, sunken brown spots on the foliage, leaf burn and even plant death.
What to do about suspected microbial contamination
Zoosporic pathogenic fungi such as Pythium and bacteria can survive in and be distributed by water6. Water sources which may not have been treated and may contain disease pathogens such as ground, river or steam water can be relatively easily cleaned up by the grower before use. The safest options are UV, ozone and slow sand filtration as these won’t leave chemical residues which may harm young, sensitive root systems. Small UV treatment and filtration systems such as those used in fish ponds and aquariums are suitable for treating water for hydroponic use and will kill plant pathogens and algae. However these are best used for treating water only, not nutrient solutions as UV can make some nutrients unavailable for plant uptake.
Even clean, clear water may contain a range of minerals, water treatment chemical and pathogens which can damage plant growth.
What to do about other contaminates and treatment chemicals
Activated charcoal (slow) filters are still one of the more reliable and inexpensive ways of removing suspected contaminates from a water supply. Herbicides, pesticides, chlorine, chloramines, and other chemicals are reduced to low levels by suitable activated charcoal filters and these can be used by small and large growers alike. If chlorine alone is a problem, aerating the water for 48 hours by using a small air pump will dissipate this chemical. Using substrate-based systems incorporating a media such as coco fibre will give a greater degree of protection and ‘buffering’ capacity where chemical contaminates are suspected.
Aeration of chlorinated water supplies will cause the chlorine to dissipate, making the water safe to use in hydroponic systems.
What to do about excess minerals
Often it is possible to dilute a water supply which may have a slight excess in certain minerals, particularly trace elements, with a higher quality water source, however for water sources with a high natural salinity reverse osmosis or distillation are the only methods of demineralization. Some crops such as tomatoes are far more tolerant of excess minerals and salinity than others such as lettuce, so this factor should be taken into account.
What to do about ‘hard’ water with a high pH
Hard water is best treated with acid to lower the pH to 6.5 before adding any nutrients to make up the nutrient solution or before using the water to top up a nutrient reservoir. This will reduce the total amount of acid required in the system to keep pH under control. Hard water also contains minerals such as calcium and magnesium, so using a specific ‘hard water’ nutrient formulation or product in recirculating systems (like CANNA Hydro Hard Water) is advised, since these will keep nutrient ratios more in balance and also assist with keeping pH in check.
References
- Date S, Terabayashi S, Kobayashi Y, Fujime Y., 2005. Effects of chloramines concentration in nutrient solution and exposure time on plant growth in hydroponically cultured lettuce. Scientia Horticulturae Volume 103(3) pp 257-265.
- Richards et al., 1996. Well water quality, well vulnerability and agricultural contamination in the Midwestern United states. Journal of Environmental Quality Volume 25 pp389-402.
- Gould J., 1999. Is rainwater safe to drink? A review of recent findings. Anais da 9 Conferencia Internacional sobre Sistemas de Captacao de Agua de Chuva, Petrolina, PE, 06-09 De Julho de 1999.
- Thomas PR, Greene GR., 1993. Rainwater quality from different root catchments. Water Science and Technology Vol. 28, no3/5 pp291-299
- Yaziz MI et al., 2003. Variations in rainwater quality from roof catchments. Water Research Volume 23 issue 6, 761-765.
- Zhou T and Paulitz TC., 1993. In vitro and in vivo effects of Pseudomonas spp. On Pythium aphanidermatum: Zoospore behaviour in exudates and on rhizoplane of bacteria-treated cucumber roots. Phytopathology Volume 83, no.8 pp 872-876.c
Rudi I&I Automan
Well-Known Member
What Ranges Should I maintain for my Hydroponic Nutrients pH, TDS/EC and Temperature?
I follow and highly recommend the following parameters for hydroponic nutrient solutions for aeroponic, “bubblers”, drip, ebb and flow, NFT, passive, rockwool and wick systems.
PH 5.1-5.9 (5.2 optimal)
TDS 500-1000ppm, EC .75-1.5
Temperature 68-78f, 20-25c (75f, 24c optimal)
The pH of the nutrient solution is a major determinant of nutrient uptake by the plant. If the pH wanders outside the optimum range of between pH 5.1 and pH 5.9, then nutritional deficiency and/or toxicity problems can occur. For hydroponic nutrient solutions used with inert media, keep the pH at 5.2 for optimal elemental uptake. It is at this point that roots most readily assimilate nutrients. These pH and TDS/EC recommendations may seem low relative to the normally suggested range, but are based upon information garnered from "Hydroponic Nutrients" by M. Edward Muckle and Practical Hydroponics and Greenhouses. They both document the low pH resulting in increased nutrient uptake and my experience has shown discernible health and yield improvements at a ph of 5.2 over higher levels.
On page 100, Hydroponic Nutrients displays both the assimilation chart for organic soil applications and another for inert medium hydroponics, which depicts the vastly different scenarios. The widely accepted soil based chart is frequently misapplied to water culture applications. His research and that done by others, documented in Practical Hydroponics and Greenhouses, indicate that iron and phosphorous precipitate in nutrient solutions at pH levels above 6. Stay below a pH of 6 by all means to avoid this problem and benefit.
The nutrient assimilation rate is further enhanced by the reduction in solution TDS/EC, which reduces osmotic pressure and allows the roots to draw the nutrients "easier". Young, established seedlings or rooted cuttings are started at 500-600ppm. The TDS is increased to 800-900ppm during peak vegetative growth. During the transition from early to heavy flowering, TDS is further raised to 1000-1100ppm. It is then reduced to 400-500ppm during the final 2 weeks of flushing. The plants demonstrate their preference for a lower TDS/EC when running a lower pH by clearly sustaining higher growth rates.
The optimum temperature for hydroponic solutions to be is 24c/75f. At this point, most elements are assimilated highest and atmospheric oxygen is most readily dissolved. Although increases in temperature increase the rate of photosynthesis, avoid exceeding the maximum listed of 25c/78f. Elevated temperatures make some elements more available, but reduce the solution's dissolved oxygen capacity, increasing root disease likelihood.
I follow and highly recommend the following parameters for hydroponic nutrient solutions for aeroponic, “bubblers”, drip, ebb and flow, NFT, passive, rockwool and wick systems.
PH 5.1-5.9 (5.2 optimal)
TDS 500-1000ppm, EC .75-1.5
Temperature 68-78f, 20-25c (75f, 24c optimal)
The pH of the nutrient solution is a major determinant of nutrient uptake by the plant. If the pH wanders outside the optimum range of between pH 5.1 and pH 5.9, then nutritional deficiency and/or toxicity problems can occur. For hydroponic nutrient solutions used with inert media, keep the pH at 5.2 for optimal elemental uptake. It is at this point that roots most readily assimilate nutrients. These pH and TDS/EC recommendations may seem low relative to the normally suggested range, but are based upon information garnered from "Hydroponic Nutrients" by M. Edward Muckle and Practical Hydroponics and Greenhouses. They both document the low pH resulting in increased nutrient uptake and my experience has shown discernible health and yield improvements at a ph of 5.2 over higher levels.
On page 100, Hydroponic Nutrients displays both the assimilation chart for organic soil applications and another for inert medium hydroponics, which depicts the vastly different scenarios. The widely accepted soil based chart is frequently misapplied to water culture applications. His research and that done by others, documented in Practical Hydroponics and Greenhouses, indicate that iron and phosphorous precipitate in nutrient solutions at pH levels above 6. Stay below a pH of 6 by all means to avoid this problem and benefit.
The nutrient assimilation rate is further enhanced by the reduction in solution TDS/EC, which reduces osmotic pressure and allows the roots to draw the nutrients "easier". Young, established seedlings or rooted cuttings are started at 500-600ppm. The TDS is increased to 800-900ppm during peak vegetative growth. During the transition from early to heavy flowering, TDS is further raised to 1000-1100ppm. It is then reduced to 400-500ppm during the final 2 weeks of flushing. The plants demonstrate their preference for a lower TDS/EC when running a lower pH by clearly sustaining higher growth rates.
The optimum temperature for hydroponic solutions to be is 24c/75f. At this point, most elements are assimilated highest and atmospheric oxygen is most readily dissolved. Although increases in temperature increase the rate of photosynthesis, avoid exceeding the maximum listed of 25c/78f. Elevated temperatures make some elements more available, but reduce the solution's dissolved oxygen capacity, increasing root disease likelihood.
theslipperbandit
Well-Known Member
Or get a bluelab Truncheon peace of piss...first tool imma buy when I'm in coco
theslipperbandit
Well-Known Member
Stop posting useless shit this is a shit talking thread