I am new to the aeroponics world and I am having some trouble with the pH. I just bought a Botanicare that holds 24 girls. I have previously been doing full soil using Foxfarm and I was told from the local Grow shop that using the same nutes would be fine. (Minus using different Grow Big) Anyway my problem is I add everything pH it at about 5.8 or so. After a couple hours the pH has moved up to 8 plus and no matter what I do it will keep changing and going back up everyday. Please help with any changes or anything I'm not doing or doing wrong. I'm just new to Hydro so unfamiliar with it. Thank you in advance!
what do you use for nutes and in what amounts? what stage of growth are your plants in? what type of lighting are you using and how close it is to your plants? give me a little more detail and maybe i can help but it sounds like your girls are using up N faster than you can give it to them. try adding a little N to your solution as you see your ph drift. also, setting your ph at 5.2 when you begin helps with the drift.
Dunny: how critical is PH?... Is it far more critical than PPM's in relation to keeping the number pretty much dead on your goal reading?... My PH tends to drop, probably a full point (8 gal. res., reciculating) every two days!... I use two 600W HPS bulbs (cooled) and a nute chiller that maintains 68*!... My girls went to 12/12 8 days ago or so!... *edit* I use GenHydro FloraGro, FloraMicro and FloraBloom (along with Andromeda and SuperThrive)
ph is pretty critical in that it will affect plants ability to uptake nutrients. it's higher for soil and other substrates, but for aero, you ideally want to stay somewhere between 5.2 and 6. a lot of times people will assume they have some sort of deficiency in their solution and try to add it back in to solve the problem, when in fact the element that appears to be deficient isn't deficient, it's just not available to the plant due to the ph of the solution. rather than solving your problem, you can potentially make it worse by adding more things in. your ph will drift no matter what you do as you're recirculating so it's going to be a fact of life for you until you decide to switch to dtw. however its not necessary bad, as long as you can maintain your ph within the acceptable range. the first problem i see with your set up is the size of your res. 8 gallon is not going to cut it for 24 plants under 1200w. you will find yourself adjusting the ph and topping it off way too often, and every time you do, there's potential for some kind of accident. get something that's at least 20-30 gallons. the larger your res is, the slower you will see the ph drift. by sizing up your res, instead of having to adjust your solution every 2 days, you can adjust or do a complete rez change every 1-2 weeks. i would top off/adjust a week after the rez change and change it the week after that. also, if your res isn't the cleanest and isn't lightproof, you'll most likely end up with some junk growing in your res which will also mess with your ph a great deal. cleanliness in general and a sterile res is a must for aero.
Thanks for the informative post Dunny!... I'm a tad late in the game at this point to change res. size, so I'll run with this set-up until I harvest!... I plan on adding a second 20 site and will look to get a larger res. at that time!... As it is now, I add approx two gallons of fresh nutes every 1 or 2 days and do a complete change weekly!... Would you still recommend a 40/60 gallon res. to support the additional 20 plants?... Also, the PH meter I'm using is just the plastic vial (1/2 vial solution/nutes and add 4 or 5 drops of test solution and read the color) and test solution!... Should I look into a digital meter (IF they're available) to get a more accurate reading?... *edit* My room actually looks like a lab. room, I keep it extremely clean and clean the res. weekly!...
if you're topping off that frequently, make sure you're not adding the nutes in at full strength. i would only add 1/4-1/2 strength solution for top offs. if you have the diligence to manage such frequent top offs and res changes, more power to you! i can barely manage filling my res once a month its hard to give advice based on the number of plants you're growing as i have no idea how dense your spacing is and how long you veg for. biomass supported is a much more useful number to use as a reference but few people are going to bother with it. i haven't done recirc in awhile but in general i size my res minimum 5 gallons per 200w of lighting. its not a set or concrete number but its worked for me personally. digital ph meters are pretty darn cheap now. <$20 online last i looked, but you don't NEED it per say. as long as you can stay within the acceptable range your plants should be fine. cleanliness goes a LONG way. i've seen lots of grows, winning and failing. the most common denominator among fail grows? dirty garden. not a problem you can solve by building/buying more crap.
LOL at your last paragraph Dunny!... I'm gonna utilize your recommendations and add a bit of what I'm doing already!... Thanks for your time Dunny, I'm sure I'll be tapping your knowledge base in the future!...
I have been growing White Widow plants for the past 3 months using a CFL 300 Watt light. Tired of waiting i have been trying to research on how to grow the most efficient way. After buying MARIJUANA HORTICULTURE MEDICAL GROWER'S BIBLE BY JORGE CERVANTES i have decided to grow with a 600 Watt High Pressure Sodium light. With 150 Lumen's per watt compared to 70 lumen's per watt using the CFL it should shorten up the process time. I also read of growing with Aeroponics. I have been watching some videos on you tube and was looking at making one myself. Here is the link to a aeroponic set up like the one i have in mind. [ame=http://www.youtube.com/watch?v=Pq1QSDLNKqE&NR=1&feature=fvwp]YouTube - Aeroponic/Hydroponic Growing Chamber[/ame] If anyone has any information on how to grow using the same set up as in this video, it would be appreciated. I have recently moved from the Canary Islands to a country where Ganja is hard to find therefore my only solution is to grow my own. I will upload pics and videos throughout the process however i must stress guidance is needed. Thanks again my fellow smokers!!!
Nutes are acidic, but when organic nutes are activated, they become a breeding ground for alkaline microbes, this would cause pH to rise, BUT, when recirculating you are reintroducing nutrients that the plant did not need at that time, you soon wind up with a huge nute imbalance. Depending on how hot you run your nutes (ppms) you can quickly develop nutrient lockout. Unless you are using DWC, you can add an outboard res and connect the two. If you are not, and if at all possible, convert it to either a high pressure set up, or a spray bar. A spray bar is cheaper upfront, and an easy DIY project, but low pressure pumps cannot atomize the nutrients, which is critical to growing baddest plants. hth
For some reason, I'm failing to have the negative experiences that some here are having!... I set my PPM's at 1250 (Gen Hydro recommends between 800/1500) and drain the reservoir EVERY 7 days!... During that time frame, my PPM's will either increase to NO more than 1300 or decrease to NO more than 1200!... I've got a li'l bitty (by the standard here) 8 gallon reservoir and I top off (2, maybe 3 gallons) with fresh nutes, generally every other day!... My nutes: (flowering) Gen Hydro FloraMicro (2 tsp. per gallon) FloraGro (1 tsp. per gallon) FloraBloom (3 tsp. per gallon) Blue Moon "Andromeda" (1/2 oz. per gallon) Super Thrive (1/4 tsp. per gallon) Nitrogen "foliar spray" (twice weekly) AzaMax "foliar spray" (any sign of spider mites) I run my PH at 6.5, but with this last refill of nutes have dropped it to 6.0!... I'm pretty diligent about watching my numbers, and I seldom have to make drastic changes!... With the exception of having water temps that approached 80* during my veg. cycle (18/6) after the lights were on for the 18 hours (corrected with a chiller set to 68*) and having the plants exhibit SLOW growth for the first 6 weeks, my plants are doing fantastic and have NUMEROUS flowers and a rich green color at this point!... BTW: This is my first attempt with the AeroPonic system, but it looks like I'll end up with a substantial yeild!...
nutes are NOT acidic. ? nitrate is acidic. p2o5 is acidic. k2o is basic. assuming they are in an aqueous solution of course. its VERY simple chemisty.... add strong N based nute, ph will fall. same for P. add K? goes up! come on people... how do you explain ph drift in a completely sterile res with no "alkaline microbes" (google that for me and let me know what comes up) raising the ph? yes, you can have a completely sterile res, regular h202 + uv treatment. author isn't using a dwc and i don't think he asked for advice regarding an hp set up. if you actually read his post, sounds like he dropped $$$ on an aerojet 24 . how bout just helping him get the most out of that for now?
sounds like your vigilance and diligence are paying off! expect to see your number fluctuate a lot more as you get deeper into flowering, but fluctuations will only screw you if you allow it to get worse and worse, but doesn't sounds like you plan on ever letting it get to that point. the girls will also start drinking a lot more water to support the increase in biomass above ground. with that 8 gallon res, you might end up having to top off even more frequently. as i suggested before, use a less concentrated solution, but i only say that in the interest of maintaining an acceptable level EC, which you seem to be doing already. i'll repeat again, 6.5 is rather high, you want to run it lower to give yourself a more manageable parameter for ph. you will start experiencing your ph drifting as high as 8, this is normal as the plants are using up all the N and K, leaving behind P. adding "bloom boosters/enchancers/etc" will also contribute to this.
Dunny: You are over-reacting. Let me clarify, the mixture of nutes (NPK) is acidic, unless one is using > 1200 ppms during Flower and one is using some ungodly amount of PK boost, which is typical of recirculating systems where it acts more as a buffer than a nutrient. TAG/HP is extremely efficient. During full on flower < 850 ppms in roughly a 2-1-4 ratio produces awesome big tight buds
so I'm in urban farmer in Dallas... Aeroponic technology on our roof.. 13 towers. Quick question, I really like Kangen water, would the pH of that alkaline water be too high for my plants.