Quote Originally Posted by tinman37
I have 36 plants in 3 gallon pots under 1000w hps bulbs. They did great through vegetative growth and lookedreally healthy upuntil about two weeks into flower, although I did not get the additional growth spurt I usually get in that first two weeks of 12/12. Starting week 3 yellow leaves started showing up, has continued to get worse and now fear i will get very little yield from these if they even live to full term. I was feeding 20-20-20 for the first week into 12é12 then switched to my regular flower food, (optimum hydroponix flower). I have tried swithcing some to straight water, someback to20-20-20, and some i have kept on the flower food, yet almostuniversally they seem to be dieing off. I have no signifigant presence of mites, temps are running at about 85 day and 75 nite. Anyone with suggestions oranswers please help. I appologize for thepic quality but hopefully u can still get a good idea of whatthey look like.
How long have they been in the 3 gallon pots? You are showing signs of nutrient lock out either from feeding too strongly, PH imbalance, rootbound conditions or salt build up.

All 4 of the things I listed can be linked together.

Again, how long have they been in the 3 gallon pots? Because of your wording I'm going to guess they've been in the pots for some time. I would do the following:

Flush with ph 6.5 water until your run off is clear. You will probably need about 9 gallons minimum and up to 20 gallons to get all the salt and nutes out.

Check for rootbound conditions and transplant into 5 gallon pots if needed.

Cut back on your nutes, you're running way too hot.

Make sure the PH of the solution you mix up to water with is between 6.3-6.8 PH.