Just wanted to let ya know the plastic over the table is the bomb & might help you if your still batteling humid conditions in your room,its been spot on for me.
If it works for you, great. I prefer not to do it that way for a couple of reasons, both those I've previously mentioned and limits on plant portability. I like to be able to move plants around in case of uneven development. My dehumidifier takes care of any humidity issues I have, which due to the peculiar circumstances of my op's location, are not only caused by evaporation from the media. Thanks for the note, nonetheless.
Yes that is what I am trying to do thanks for the great diagram.
but how would one hook up intake fans to the thermostat controll without the power
looping back causing the intake to run continually on the msc. I want the intake to shut of and on with the thermo switch and not msc when the switch is open (disabled) .. maybe some sort of diode relay that only lets power flow toward the fan?
thanks for your time Al.
If you have 'power looping back causing the intake to run continuously' you've wired it wrong. Follow the diagram I drew for you. No diodes are necessary in this situation and in fact with AC, would create problems. Check your wiring & try again.
I took off this site when you started a new job a while back, I learned so much from you.
Glad to see your back teaching the masses.
Thank You
Thanks for the thanks.
Hey Al iM not a big social person even on the internet. But when I first came to RIU I went to the forums section just off of instant and I knew I wanted to do hydro and I went straight to your thread harvest every 2 week and I immediatly started reading non stop very profound shit bro. Then I was so excited you seem like a celebrity to me, I was like dame I wish I could of been around when you was, just to think of a question to get an answer. lol 4 real. An d I almost got a lecture from you on this post WOW! Thanks bro But I really needed the info not just some Q&A shit. Anyway Al can you refer me to some electrical litature so I can learn the basics to get my issue solved the way you learn? Im really stressing this shit now I did not expect this much $$$$$$$$ and complex knowledge. Espically with electrical everytime I say this is it with spending $$$$ theres another important issue. I spend almost 4-5k just to get my bull shit yields trying to get to your yield and op going now electrical. Is there any thing else vital I have to worry about? Can you do a thread about your thoughts on electrical and the price on getting your op going exactly the way you going now? Thanks bro your a scientist.
Thanks for the thanks.
The key to good yields is making your op produce certain conditions. It has to maintain the correct temp (24-26C) & RH (40-60%) while also having sufficient ventilation to remove heat and introduce fresh, CO2-laden air. The op has to be constructed so exhaust air cannot easily be re-drawn into the op. You need accurate measurement devices so you KNOW what the temp, RH, nutrient TDS & pH are at all times. When you're sure of what's going on, you can make corrections as needed- and you
will get good results. I probably won't do any new threads on RIU. It's hard enough for me to keep up with this one. If you have any specific questions, feel free to ask them here.
Hey nice setup,
What kind of air stone size are you using in your Rez?
I'm looking into requirements for my 120 liter res for flood and drain perlite, any suggestions? Also would love to see some pics of your root development inside your tables( maybe when you chop). Thanks
My air "stones" (they're not stone) are foam sleeves with a stainless steel tube core which keeps them from floating. They're about 250-300mm long. Will post pix the next time it's convenient to do so.
u got any advice on meally bugs?
and what kind of bulbs should i get I'm thinking of 4 400 hortilux blues or 2 600s and a 1000or maybe 4 400s plus a 1000
No advice on mealy bugs at all. Never seen them in an op- had to look them up on Wikipedia to even know what they are. A broad spectrum insecticide, applied weekly for a while, should make them go away.
As regards the lamps- all you need is HPS for flowering- they'll work fine for mums as well I use 2x1000HPS over 4x900mmx900mm trays for my flowering are & 1x400HPS for the mums. Fluoros in my clone box. The fewer lamps, the better, in most cases. Ballasts waste a certain amount of power in converting voltage and controlling current to suit the lamp, so fewer, larger lamps are better. You do not need to have broad spectrum lighting for flowering plants. In flower, the plants mainly need a red-yellow spectrum, as they'd get outdoors in autumn. It's not necessary at all to add blue lighting for flowering plants. Waste of time & money.
I know al uses 1 ml per liter of 50% grade. But I can only get 29% so I would have to use 1.7 ml per liter Which would be over 255ml every 3 days! Over 1 liter every 2 weeks for 1 res. That seems a bit much.
For a large res, that sounds about right. You may not be able to get anything stronger than 30% in North America. The story I'm told is that 50% is restricted as it may be able to be used in making TATP, a highly unstable but easy to make explosive commonly used by terrorists. I'm not into amateur bomb-making, so I don't know if that story is true or not. You may be able to get 50% grade from chemical supply houses or you may be able to persuade your local hydro shop to order the stuff in from said chemical suppliers.
....yeap, I use h2o2....I use the 30%, and I typically only add a ml per gallon. I try to stay focused on res temps and bubbles in the res also.
If you're keeping pathogens under control with 1ml per 3.78L (1 gallon) of nute soln, fine. BTW, make friends with the metric system. It's SO much easier to use than ounces/pints/quarts/gallons etc.
al i got a question about how h202 works since your a scientist. what would happen if i just dumped 6.9 ml of 29% h202 in a gallon of water but i didnt use the water to grow with. to be more clear after i dump it in i know the oxygen level will be higher. will the oxygen level in the water be higher permanently and never leave because its liquid oxygen and it isnt being givin to the plants and sucked up by the roots? if its possible for the extra oxygen from the h202 to leave the water without being sucked up by the roots then how long will it last until its totally gone and can you explain scientifically how its able to leave since i think it stays liquid oxygen? im just trying to figure out if the reason you have to give h202 to plants every 3-4 days is because the plants are using it all up or if it breaks down and disappears even when plants arent using it up. thanks
H2O2 breaks down into GASEOUS hydrogen and oxygen. Water will retain a certain amount of dissolved gases (more retention of dissolved O2 when the nute soln is cooler) but they will leave the soln through evaporation in time. There's a number of factors which will change the rate at which dissolved O2 will leave the solution; size of the res, nute soln temperature, etc. When H2O2 comes in contact with dead organic matter or microbes, it breaks down quickly into H2 & O2, so the greater the pathogen load in the solution, the faster the H2O2 concentration will drop. You can get test kits which will indicate the amount of H2O2 in your nute soln.
you have a chiller for the res? what temp do you keep it at?
If you realllly want to know how much dissolved O2 your water will hold, you can calculate it- see
http://antoine.frostburg.edu/chem/senese/101/solutions/faq/predicting-DO.shtml
However, in a hydroponic grow op, it's generally enoguh to know that keeping your nutes cooler will increase the dissolved O2 in solution. However, making it
very cold will reduce the roots' uptake of O2:
From:
http://www.simplyhydro.com/nutrient_temp.htm
Nutrient Temperature - Oxygen and Pythium in Hydroponics
by Dr. Lynette Morgan, Courtesy of NA Greenhouse
The hydroponic nutrient solution is not just a mix of fertilizer salts and water, there are a number of organisms and compounds commonly found in our hydroponic systems that we need to be aware of. One of the most important of these is dissolved oxygen, which is vital for the health and strength of the root system as well as being necessary for nutrient uptake.
Most growers are familiar with the need to have some form of aeration in their nutrient solution - whether they be in a recirculation or a media based system. In NFT systems, this is often accomplished with the use of an air pump or by allowing the nutrient to fall back into the reservoir, thus introducing oxygen. However, the effect of temperature of the solution on the dissolved oxygen levels and on root respiration rates also needs to be taken into account. As the temperature of your nutrient solution increases, the ability of that solution to 'hold' dissolved oxygen decreases. For example, the oxygen content of a fully aerated solution at 10°C (50° F) is about 13ppm, but as the solution warms up to 20° C (68° F) the ability of the liquid to 'hold' oxygen drops to 9 - 10ppm, by the time the solution has reached 30° C (86° F), then it's only 7ppm.
While this may not seem like a huge drop in the amount of dissolved oxygen, we have to remember that as the temperature of the root system warms, the rate of respiration of the root tissue also increases and more oxygen is required by the plant. For example, the respiration rate of the roots will double for each 10°C rise in temperature up to 30°C (86° F). So the situation can develop where the solution temperature increases from 20° - 30° C (68° - 86° F) during the day, with a mature crop and a large root system, then the requirement for oxygen will double while the oxygen carrying capacity of the solution will drop by over 25%. This means that the dissolved oxygen in solution will be much more rapidly depleted and the plants can suffer from oxygen starvation for a period of time.
The symptoms of oxygen starvation which can occur in both NFT and media based systems can be difficult to pick up as they are very general signs. Media based plants are just as prone to oxygen starvation in hydroponic systems as those grown in solution culture, but here we must also take into account the 'air filled porosity' of the media used. This is simply how much air can permeate between the particles in the substrate and selection of a free draining media which won't break down will ensure that maximum aeration is going to reach the root zone. Injury from low (or no) oxygen in the root zone can take several forms and these will differ in severity between species. Often the first sign of inadequate oxygen supply to the roots is wilting of the plant during the warmest part of the day when temperature and light levels are highest. Insufficient oxygen reduces the permeability of roots to water and there will be the accumulation of toxins, thus both water and minerals cannot be absorbed in sufficient quantities to support plant growth particularly under stress conditions. This wilting is accompanied by slower rates of photosynthesis and carbohydrate transfer, so that over time, plant growth is reduced and yields will be affected. If oxygen starvation continues, mineral deficiencies will begin to show, roots will die back and plants will become stunted. Under continuing anaerobic conditions, plants produce a stress hormone - ethylene which accumulates in the roots and causes collapse of the root cells. Once root deteriorization caused by anaerobic conditions has begun, opportunist pathogens such as Pythium can easily take hold and rapidly destroy the plant.
Another more visible and longer term effect of oxygen starvation which also occurs in waterlogged crops is leaf 'epinasty'. Epinasty is a downward curvature of the plant leaves, resulting in plants which look wilted. If the oxygen starvation continues and is severe, then eventually leaf chlorosis yellowing, premature leaf and flower abscission will occur.
There are a number of things we can do to make sure our nutrient solution is carrying sufficient dissolved oxygen, and this is important when we consider that many of the root diseases encountered in hydroponics have occurred because the root system was damaged in some way, with anaerobic conditions being a major factor in many situations. The first most important factor to remember with oxygen is that the best way to introduce this gas into the nutrient is to have the solution fall back into the reservoir, and the greater the drop height, the better the aeration effect. Breaking the flow up into a fine shower also assists by introducing more air bubbles into the tank. Secondly, while nutrient EC does reduce the oxygen carrying capacity of the solution, the effect is very small and temperature has a much greater influence on oxygenation. Reducing excessive solution temperatures will ensure more oxygen can be held by the solution and the rate of respiration by the roots will be kept down to optimal levels. Thirdly, factors such as nutrient flow rate, channel width, length and slope have a large effect on oxygen levels- faster flow rates, greater slopes and shorter channel lengths all assist with prevention of oxygen starvation.
Perhaps one of the most common problems in hydroponic systems is the Pythium pathogen and what many growers don't realize is that Pythium being an 'opportunist' fungi, often takes advantage of plants which have been stressed by a combination of high temperatures and oxygen starvation in the root zone. Pythium is usually described as a 'secondary infection' meaning that the Pythium spores which are actually common in just about all hydroponic systems, don't actually attack the plant until it has been damaged in some way. Even very clean hydroponic systems and grow rooms which are isolated from the outdoor environment will have some Pythium present as these fungal spores are naturally present everywhere on a world wide scale - in the water, soil, vegetation, carried in the air and in dust, so it's difficult to eliminate the source of this disease. However, one way we can reduce the 'spore load' is to sterilize any water supply which may be contaminated with high levels of Pythium --- water from dams, and streams should always be sterilized before use for this reason if Pythium is a problem.
Under the right environmental conditions, virtually every plant species is vulnerable to Pythium, which not only causes 'damping off' of seedlings but causes root and stem rot of older plants. Symptoms of Pythium on older plants are a wet rot, root systems will be browned, roots hollow and collapsed. Plants may appear to grow poorly and wilt for no apparent reason --- indicating that an examination of the root system when called for. Pythium has an optimum temperature range for infection of plants, which is generally between 20° - 30° C (68° - 86° F), although infection can occur outside this range when damaged plant tissue is available for rapid colonization by the pathogen. Low concentrations of Pythium that may not cause problems at lower temperatures will be disastrous at higher temperatures, particularly where the warmer conditions are associated with a lack of oxygen in the root zone and plant stress.
The best preventative measure against Pythium attack is a healthy, rapidly growing plant as this is an opportunist pathogen and will enter at the site of tissue injury or if the plants are overly succulent, weakened or stressed for some reason. Often root damage during the seedling stage as plants are introduced to the hydroponic system is a danger time for Pythium infection. Pythium is of greatest threat during the seed germination and seedling development stage when plants are most vulnerable to attack, and adequate control and elimination of the pathogen during this stage is the best preventative measure of Pythium control in hydroponic systems. Strong healthy plants will develop resistance to Pythium attack during the seedling stage and this will prevent problems at a later stage of growth.
Other preventative measures include the use of a well drained media, thorough disinfection of all equipment between crops (a strong hypochlorite solution --- bleach is the most effective), and control of pathogens during the seedling stages with a suitable fungicide, long before they are introducing into your hydroponic system. Occasionally a very high spore load, combined with excessive temperature will result in Pythium attacking even healthy plants, if this is the case, it is likely that there is an active source of spore production present and the system must be shut down and disinfected. Some growers have found the use of wetting agents and chlorination of the nutrient solution beneficial in limiting the damage caused by Pythium, however extreme care needs to be taken when using products such as calcium hypochlorite as to much active chlorine will kill sensitive plants. UV light, hydrogen peroxide and ozone have also been used to kill Pythium spores in the solution, however these can have major effects on some of the nutrient elements in solution and careful consideration should be given before using these methods. Sterilization of the water supply with these methods, before nutrient are added however, is effective at reducing or eliminating Pythium from the original water supply.
Therefore by ensuring your plants are healthy and stress free, you will not only get the highest growth rates possible, but also prevent problems such as Pythium infection occurring. The variables to remember with regard to the nutrient solution is that aeration is vital to maintain the dissolved oxygen levels, temperatures should be keep within an optimum range and Pythium is always present, but a healthy plant is the best measure of protection against a disease outbreak. About the oxygen requirement of plants when in flower...its not always the case that plants require more oxygen because they are in flower, a plants oxygen requirement is linked to the size of the root system, temperature and nutrient uptake rates, rather than the presence of flowering. Since plants such as tomatoes tend to have a rapidly developing root system at the time of flowering, it's important to maintain adequate oxygen levels. With tomatoes, the requirement of oxygen in the root zone increases gradually up until the time of maximum fruit load and rapid fruit expansion, where the high rates of nutrient uptake increase the oxygen requirement quite dramatically. On the other hand, if oxygen is deficient during flowering, then the flowers and subsequent fruit may drop off as a result, or they may be undersized and may fail to pollinate.
Dr Lynette Morgan is the Director of Research at SUNTEC International Hydroponic Consultants, based in Manawatu, New Zealand.
hellraizer, i think you and potpimp are giving two different answers on this subject. potpimp seems to be saying it never leaves and your saying it does. id like al to clear this up for us. thanks for the responses
H2O2 certainly does break down into gaseous H2 & O2 and will exit the soln eventually. As a general rule, H2O2 will remain in soln for 2-4 days depending upon various factors. This is why I recommend re-dosing the soln every 3-4 days.
its doesn't ever "leave" it just changes back to water, sort of the same thing that ozone does with bad smells. It just gets used up, and needs to be replaced.
Some of the H2O2 converts into water, some departs the soln as gaseous H2 & O2.
when i say leave im talking about the extra oxygen it adds. lets say sitting water has an oxygen level of 5.5 ppm and when you add h202 it then becomes 8.5 ppm. if roots arent taking up the water will it permanently stay at 8.5 oxygen level or does it return to 5.5 no mater what?
The dissolved O2 holding capability of water is dependent upon temperature. The dissolved O2 level will eventually drop as th O2 exits the soln through evaporation.
Water is H2O, so it is 33% oxygen always. (333,333 ppm).
Hydrogen Peroxide is H2O2, so it is 50% oxygen (500,000 ppm).
So by adding a little h202 you are not really adding much oxygen at all. You are adding hydrogen peroxide which works to kill pathogens, not increase the level of oxygen in the water.
The reason for using H2O2 has very little if nothing to do with oxygen at all, simply the effects of adding a sterilizing agent.
H2O2 works BOTH to kill pathogens and oxygenate the solution.
thats false Trueno. my friend has an oxygen meter and sitting water comes up as 5.4 approx ppm and his bucket system water with expensive airstones and constantly moving water comes up as 6.7 ppm. he did a test and added h202 to his system and the meter read 8.5 ppm afterward. from his readings the h202 does a tremendous job at adding oxygen. the problem is my friend wants to argue with me and he doesnt want to run the type of test i want him to run. i told him to dump h202 in water that has nothing to do with growing and see if it still reads 8.5 like 2 weeks later thats what im trying to figure out. when the h202 is in his system at 10 ml a gal (29%) the meter slowly goes down as the plants use up the oxygen and by his calculations its totally gone in 24-36 hours
Precisely.
al i wish you were a member at icmag so you could respond to this thread
https://www.icmag.com/ic/showthread.php?t=224381
this guy says he put 3 ml of 29% h202 in his aero cloner and it created slime everywhere. he also says he gave his plants 10ml a gallon of 29% h202 and all 4 of his plants died. i know he's full of it but i wish you were a member so you could respond there
H2O2 will not 'create slime' anywhere. I don't know what this guy is doing wrong, but he's certainly doing something wrong. I don't have the time to chase up every inaccuracy on RIU, let alone on other boards. It's sufficient to say that this fellow is mistaken. 10ml of 29% H2O2 in 3.78L of water is about 3x the usual dosage I run in my tanks, but it's not enough to hurt anything.
I don't half wonder if this guy bought a very old container of H2O2 which had broken down into mainly H2O & O2 (the latter which escaped as a gas). That would explain the 'slime' (probably an accumulation of pythium) and the death of his cuttings from rot, since there was no H2O2 in his solution to kill the pathogens.