How do you feed aero plants based on PPM/EC?

livinlegend said:

I never said you'd veg it for 9 weeks. In fact I'm running SoG so I wouldn't veg at all, I'd flower 36 clones directly after they root. Could you have answered my question instead of criticizing what I was saying?

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livinlegend said:

I found this:

-snip-

If this is indeed true that the next day you check ppm and if its higher the plant has too much nute, if its lower the plant has too little. If its stable its perfect. I think this will greatly help me.

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livinlegend said:

This is what I meant to post

How do I tell if my PPM/EC is too high or too low?

It's simple to find out if you are using too much food or not enough by watching the nutrient concentration levels in your tanks day to day. Don't be concerned with the exact reading, rather watch how it rises and falls from each day to the next. The differences between when you put the solution into the tank and the readings you get several hours later or the next day are what tell you if your plant is eating, drinking or happy.

Start with 1.00 EC (or a SAFE nutrient strength). Next day, if it reads 1.4, it means your plants have been using water and your nutrient solution is becoming more concentrated. This means the concentration of nutrients is too high, so you dilute.

If the meter reads lower than the previous day, 0.7 say, it tells you that the plants are eating nutrients faster than they are drinking water, so you should increase your nutrient strength. If it remains the same, your feeding schedule is on target for now. The nutrient/water intake fluctuates with the growth of the plant, so you must continually monitor it day to day.

Your plants will tell you the optimum nutrient levels. When they are receiving optimum food and water, the readings remain constant. The more you do it, the easier it gets. The reason no one can tell you what PPM/EC levels to use is because every garden is different and every plant has different requirements due to their particular environment. That's why you have a ball park starting figure, but after that your plants will tell you almost exactly what they require.

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fatman7574 said:

No lowering of EC in budding and no flushing.

Using intermittant medium pressure low flow mister heads in aero tubes I run only 0.3 EC from the just rooted stage and ramp up to 1.0 EC where the level remains until harvest. My bloom formulas is the same as the veg formula except with boosted magnesium via magnesium oxide, MonoPottasium Phosphate and chelated iron. I use no ammonium nitrate, no ammonium Phosphate or Phosphoric acid in my formulations nor do I use silica phosphate. I get adequate ammonium-N from other nutrient chemicals so as to limit to ammomium-N to no more than 5% of the total nitrogen content of the nutrient solution. I use sodium hydroxide to raise my pH. and nitric acid to lower my pH. I use aerated RODI water. As my RO water calcium level is zero I set my calcium level in my nutrient fomulation at about 60 ppm. The pH and conductivity and auto water top off is all automatic. I drain and replace nutrients weekly, mainyly because I get tired of testing the calcium level. I do not reduce the EC, once it is at 1.0 it stays at 1.0 until harvest. I am hoping soon to lower the EC even further once I switch to finer micron misters.

My drying is initially in a sealedvroom with room with CO2 enrichment with a dehumidifer set at 20% humidity. Then the product is put in cellophane bags unsealed in an airtight box with all air removed and replaced with CO2. Every two days the bags are opened and the product emptied onto cellophane sheets and a bit of shaping and trimming is done and the bags refilled but left unsealed. The bags are put back in the air tight box and the box again has all air removed by CO2 flooding. This continues for usually 14 days. At that time the products are cured enough to seal the cellophane bags in steel cans. Dogs can not smell through sealed steel cans. Resins do not stick to the cellophane as they do to plastic bags. Really. The product does not taste like chemicals or chlorophyl and the leaves are green. I always wear latex gloves.

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tree farmer said:

what type of equipment does it take to be able to check the levels of individual nutes(i.e. calcium,nitrogen) like you do. i understand that you can formulate the start levels to whatever percentages you want but after even a few days can a person test to see what concentration of an individual element is left.

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fatman7574 said:

Calcium is easy to test as the reef aquarium suppliers have developed a simple ion specific testing meter. It is sold my American Marine (Pin Point)and is sold at most aquairum retal stores. Some what expensive at $260. http://www.marinedepot.com/American_Marine_Pinpoint_II_Calcium_Monitor_Single_Item_Monitors_Controllers_for_Saltwater_Aquariums-Pinpoint_Monitors-AM1121-FITEMOID-vi.html There are also many reagent type test kits that run about 25 cents per test to run. Calcium tests are merely titration tests where you add a dye and add acid drop by drop until the color changes.

I have ion specific electrodes for most of the fertilizer chemical tests and also use a Hach spectrophotometer. By far the most expensive testing is with the ion specific electrodes as they do not sell cheap (average about $700 each). They are quick though. Just plug the electrode cord into an ISE pH meter and stick the electrode into the water. Well almost. All the testing equipment and reagents for manual tests and spectrophotometer tests are typically designed for drinking or waste water (they are the major users as EPA requires testing of water and waste water) so your nutrient water very often has to be put in a flask and diluted with RODI water before testing as most tests are for much lower levels such as 20 ppm instead of 200 ppm etc. For an example a high range test for nitarate is 4 ppm, therefore for maesuring the nutrient level you would start out by diluting 10 ml in 90ml RODI water , and dilute 10 ml of that dilution into 90 ml of RODI water, and now do that one more time to beable to get a reading on a nutrent of up to 4oo ppm. I use pipettes that are slim graduated measuring tubes so that I can simply use smaller dilution amounts. ie I can start with 1 ml in 99 ml of ro water for example. In reality I use a digital pipette but those are not commonly used by most people who s do few test as they astar at about $100 each. They are like the ones on TV shows like CSI where the lab tech draws up a little fluid and squirts it into a little vial. Then you just eject the disposable tip so each tip is only used omn one sample or dilution. It is not uncommon to just test the full strength water and if the meter says out of range then it is dumped into a flask and diluted with nine parts of Ro water then a new reading is taken woth the diluted sample. This method continues until you get a readin that is not out of range. Then you just mulitply by the dilution factor. Once diluted is a multplier of 10, if that is diluted then it becomes a multiplier of 100, then 1000 etc. There are reagents with different reanges but none sually have a really high range. The reagenst for use without the Spectrophotomers are genearlly in individual kits with color comparison wheels. the kits run abourt $75 to $150 each. The reading accuracy of the spectropohotometers si not prone to human vision errors and is really the cheapest manner of testing. There is also a hand held meter called a Hach 950 colorimeter, but even used they sell for at least $650 or more. they typically use the same reagent packets as the spectro photometers.

Probably the cheapest manner of setting up a home lab for nutrient testing is buy a used Hach spectrophotomer on eBay. This is a model DR/2000. You can usually buy one for abour $50. Either a DR/200 or a DR/2010 or any number higher than that will test any reagen testable nutrient. Organic nutrients are a different ball game.

The premixed reagents for testing are typically sold for 100 tests. The typical cost is $12 to $25 per 100 tests.

You would need at eBay costs about $50 worth of additional glass ware such as test cells, small flasks and graduated cylinders etc, but all the directions and manuals are readily down loadable for free from Hach.

Few people ever test for the micro nutrient levels so figure testing only for the major and secondary at $25 per eack and $100 for a spectro, meter and acessories that maens about 6 test parameters at (6 * $25 + $100) = $250. add another $25 for each micro nutrient you wish to test for. It sounds like a lot but each $25 is 100 tests. Mixing your own nutrients you will typicallly find that once you have done enough tests to dial in the needs for the particular strain and growing n method you are using you will just mix the formula based on your needs and top off for about aw week and dump as the new nutrient cost is less than the test costs if you have only a small reservoir for one grow room. One test of all six majors is going to cost about $1.50. My nutrient cost is negligible as my water cost for RODI water is higher than the nutrient cost so I base things mot re on that. My water is about $1.50 for a reservoir. So it is a matter of test once aweek and add specific fertilizer or dump once a week. The cost is about the same. So I just use a conductivity analyzer/monitor that runs 24 hours per day and that activates a relay to automatically add nutrient concentrate as needed by a small peristaltic pump. I did run many tests prior to this to determine the highets and lowest demands for nutrients through out the whole grow cycle based uopn indivaidual nutrient declines in the resrvoir daily. I just picked what seemed like good starting ppms for a nutrientt formula and mixed to 1 EC and went from there.

The rest below is sorta out of left field.

Chemical nutrient science and chemical nutrient formulation and chemical nutrient monitoring is a very well known and well documented science. There are no hidden secrets and it is all pretty straight forward. It is one of those beat a dead horse things with some of the old technology growers though that won't let go of old methodologies that do not apply to higher tech grows. The only real changes are just based upon higher technology being used such as better nutrient delivery sytems (aeroponis especially misting aeroponic rather than low pressure systems), air conditioning, HID lighting, dehumidifiers and metered CO2 usage that have changed the nutrient issues. Even then it is merely going through the steps to finf what everyone should find if they are serious growers, "the individual needs of your prinicipal strain based upon the environmental parameters provided by the technologiacal levels of your system." But then there is always the question of are you not provideing the balance you need for optimal plant health and growin efficiency by trying to use an inadequate low techmethod of providing good growing parameters that are insufficient. For example if you have great temperature control, a great nutrient delivery system and great lighting but inadequate CO2 delivery system as you are merely using ventilation but providing high parameters in every other area, things the grow would be much harder to manage than if you just added the extra CO2 needed to match up all parameter levels. This may seem from left field but all things are intertwined so that it seems like when ever you max out one delivery method of one growing requirement then you find another that is lacking.

IMHO Mixtures of low tech and high tech are harder to manage than systems of all high tech or all low tech. Balance is a hard thing to find. Like trying to ride a standard bicycle backwards and forward. Not many well ironed out unicycle growing systems like there are for unicycle s for bike riders.

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tree farmer said:

I agree your only as good as your weakest link. i know your a fan of AC and CO2 and theres no doubt yield will increase when these parameters are controlled using them. Also though ,without air or watercooled lights it will take almost a 3rd more eclectric to cool the room. And if water cooled lights are used than you have to have a large supply of cooled water(tank buried, swimming pool. lake etc.) or have to use a chiller (more electric.). If a person has access to free cooling of the water than the effiecency of the room will definatly increase but without that theres no free lunch. co2 has to be created someway. if tanks are used thats still an added cost and only so efficient depending on the size of the room. if propane is burned than you can increase the cost of cooling the room (more Ac more electr) I dont know the cost break down but without free cool water im not sure the KWH used arent much different. What you think.[/QUOTE}

I am not sure what yomean by a third more electric to cooll the room. If you mean that wtaer cooled or air cooled system remove 1/3 of the heat created by the lights, I bek lieve they can definitely do beter than that. Air cooled lights attached to insulated ducts should remove about 50% of the heat and water cooled about 75% if the the majority of the water lines are insulated. However most people do not insulate their ducts or use insulated HIVAC flex ductinfg so the air cooled lights probably remove only about 35% to 40%

I have tried to avoid the cooling aspect as much as possible to avoid a fire storm. However, I simply calcualte that for every 1 kWh watt of lights I run I need to run 0.85kWh of airconditioning and chilling. At least during weather with ambient tempearture above about 60 degrees. I do not vent grow room air either inside or outside. I use carbon but only inside the grow room so that odor minimal when servicing the room. I build rooms that you do not walk into. They are serviced through metal clad insulated weather stripped doors. The rooms are never wider than three feet so they can be easily serviced from one side. The walls, ceiling and floors are all fully insulated with 5-1/2 inches of foam. They are covered inside with FRP and and that is covered with Alomet reflective aluminum for 24" above the pot heights.

I really do not want to talk openly about my operting temperatures or CO2 levels etc. but there is an air conditioner evaporator inside each grow room, the compressors is out side the houses, and an entire small window airconditioner sits inside each grow room. The fully inside window air conditioners work for back up dehumidification that normally only run occasionally at night and they are used more in the winter. It is on drawer glides and can be rolled into a duct that allows its heat to be exhausted into the house in the winter.

The lights , even the long tube CFC's are all water cooled. The chillers are made out of a one ton window airconditioner. They each chill an insullated tank of water to 50 degrees in the winter and 40 degrees in the summer. The water for the reservoirs circulates by a thermostatically controlled pump through titanium tubes that run through the chilled tank and there is a titanium tube through each reservoir. All the reservoirs stay very nearly the same temp running on just the one loop for each grow rooms reservoirs.

The water for the lights runs constant as long as the lights are running, there is a flow switch on the water line for the lights that shuts off the water if the flow slows or stops. There is also one on the chiller exchangesr water line. The system is balances out with CO2. Even with all the climate control the system puts out a good deal more than 1 gram per kWh and that includes all electricity used not just the power for lights.

Nobody ever asks why the air conditioners run all year round. The few people I allow in my office look curiously at the wall full of doors but few ask why. There is a set of 32 inch doors every 36 inches. They have regular locking door hardware. The few people that ask are told they are closet doors. My real closet doors match the grow room doors. I have reef aquariums also so people do not say any thing about an insulated tank with hoses going in and out the sides.

If considering the yield costs to a low system without full climate control do I think the controlled grow rooms pay off well. Absolutely. Would I recommend it to the typical grower. No. For larger growers yes I would strongly recommend it. Would I utilize cold ground water and cold outside air if I did not rent but instead owned yes. If I owned my own home I would install a natural gas power combination generator and heat pump/airconditioner, but I would also use winter cold air for cooling. I would remain hooked up to regular electrical service for regular household power for appearances sake.

It is kinda hard to beat a heat pump when they can waidely be bought with efiiciency factors of over 2.5 or higher. That means you get out 2.5 times the energy you put in. Where I am though they are only really any good for cooling. Water is too cold all year arounfd for exrt tracting heat, and the air is definitely to cold 6 months per year. Both will take excess heat real well though all year round. actually we get about 6 hours of warmth per day for about 90 days per year. water temp and ground temp 5 foot down is 34 degrees all year round.

I have a few frinds with high RODI water demands as they service reef tanks and some fresh water tanks for a living. They use tap water run through the water cooled lighs to warm the water that is then sent through the RODI system.. As they operate better at warmer temps this improves there out put and it means there chillers run a lot less. I also set up a water cooling loop heat exchanger to coo a friends 1200 gallon reef sytem made up of many smaller tanks all interconnected. As he also uses huge amounts of RODI water he tempers the 34 degree water by using it to cool his reef system. There are also many people up here who put tanks of water and 55 gallon drums of water in their grow rooms to temper the rooms. The day time excess heat is taken in by the water and slowly released after the lights go out. As this is typically done with the higher temp 12/12 hour grow room it is relatively easy to calculate then fine tune the amount of water that need to be in the room.

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