Hi, I hope someone can perhaps give me some advise, I must add this is the first time I have grown, I am using an active hydroponics set up, I.E. water is pumped to the plants using a spray bar, then water is drained back into bucket. substrate is pea sized inert pellets, the feed strength using a wand reads 2.0 EC or 1400PPM or 20CF, the feed is I believe a standard A & B feed powder form, PH 6.2, I am watering them continuously 24 hrs a day, 5weeks old from seed around 2ft tall very bushy, the Temp isn't high around 71%f to 74%f lights on, lights off Temp is around 68%f, 12/12 cycle, so I must assume the water is a little cold in the buckets, 2 600 watts lights, Humidity is around 40, does go up to around 60 lights off, huge amounts of fresh air drawn in, "perhaps to much in the winter" good ventilation, but I switch of all ventilation when lights are out ( is this correct ) I find if I don't it does chill the grow room, growth rate now is around 2 " per day I have noticed a few of the plants leafs tips have a curl upwards, and one plant the top leafs are a little pale in colour, I also spray them with a feed strength 2.0EC PH 6.2 twice a day, once just before lights on, then again about 4 hrs into light cycle. the lights are around a foot to 18" away from the plants. I am told that since I am using an active system that my feed strength can be cut down, and this might be causing the problem, the problem is mild, but I am worried a little, Sorry for being a long winded, and I hope some one can point me in the correct direction. I have gotten all this from books, but experience cant be bought Thanx in advance Gazz
You have a couple things wrong at the moment. 1.. an ec of 2.0 is too high. 2.. the PPM is ok but should be a little lower like 1200 (1400 is pretty much the max at towards the end of flowering) 3.. your ph of 6.2 is way wrong for Hydro... PH has to be between 5.5 and 6.0 no higher than 6.0 Also spraying should not be done continuously, it should run for a few minutes and then off again for a while, this is what teases the roots to grow and hense the plant growth. So far it sounds as if your not having a problem with growth even though your constantly bathing the roots in solution. so you can maintain that if its workign for you but you have to regulate your ph for sure. The curling leaves tips is because of nutrient burn and PH blockout.., curling leaf tips could also be heat stress but you didnt give details on your lighting. PPP is a very very strong plant, and hard to kill, if it had been any other strain you would have seen big problems already.
Thanx DierWolf, will correct ASAP, Having a PH problem, just tested the water, and it reads 7.4, when I made up the solution 5 days ago it was EC 2.0 and the PH was 6.2, now the EC is 1.8 and the PH is 7.4, I mean whats happening, is it possible the Pea type substrate is Alkaline? Again Thanx Gazz
Yes... try rockwool next time. unles you got a cat thats peeing in your res LOL. Oh wait that would be Acidic LOL.