Plants stopped growing PLEASE HELP

Hello,

My plants stopped growing a few weeks ago. I have 4 plants, all started from clones. They grew fine and very fast and looked so healthy I couldn't have been happier, at first (for about 1 month). They reached about 2 feet tall, and then all the sudden the leaves started to turn yellow, crisp, with brownish red spots on them, and the plants just quit growing.

Here's my specs:
Hydroponic.
white rhino strain.
nutes are general hydroponics micro flora 5-0-1.
I use 8ml / gal of nutes in an 18 gallon bucket, but only fill it with 12 gallons of water (12 gallons of water, so 96ml of nutes used).
PH between 5.3 and 5.9
running three 400w HPS lights, 24/7.
heat is 72 degrees at night 82 degrees during day.
humidity is normal, never high.
fresh air is pumped in from outside my home.
oxygen is delivered to my roots via a simple fish pump system, and I'm sure they are getting good amount of oxygen to the roots.

Additional information:
I was told to use the solution of nutes I mentioned above, and as the plants drank about 1 gallon of solution, add 1 gallon of fresh water until 12 gallons of fresh water were added, and then start a new FRESH batch of nutes. repeat process.

I never got this far. WHen they were young and first growing, they only drank about 2 gallons of water. then they stopped growing and hardly taking much water/nute solution at all. I thought there was a nute / PH problem, so I gave them a fresh batch of nutes.

this is when I noticed my PH meter was out of calibration, and reading 1 point high, so a reading of 7.0 was really 8.0. I fixed this. Now, i figured I screwed all batches of nutes up, and gave them another new batch, and adjusted PH to 5.3. Still no growth.

So I read the forums here and thought I had NUTE BURN (3 batches of full strength nutes within a 2 weeks). So, I've been flushing my plants for over 3 days now with nothing but water, no nutes, and have still seen no change, though in the 3 days they have drank over a gallon of water.

I just went through the forums again, an believe I may have OVER FERTILIZED my plants. Maybe I shouldn't have given them a full strength batch of nutes while so young??? Can this stop plants from growing???

or:
I'm now wondering if maybe I did't have nute burn, but nutrient lock out. Since my PH meter was reading off, i may have been locking out all nutrients.

I just don't know. I don't understand how they can just STOP growing. I'm at my wits end here and afraid my babies are going to die. I'm going to take clones today for just in case, but am not even sure they will live since the plants are so stressed...

Any and all help will be appreciated.

Sorry so long winded but I wanted to give a clear picture of what is happening here.

Thank you for reading,
-Snut

Lock out is a possibility I suppose. I hope your roots didn't rot. But, maybe take the lighting down to 18/6 or something similar. My plants stopped growing and I changed from 24/0 to 18/6 and growth started again. I also put the tiniest drop of superthrive in my bucket and the plants liked that. I'm also a noob though, so I could be way off base. Good luck.

TheBlazehero said:

Lock out is a possibility I suppose. I hope your roots didn't rot. But, maybe take the lighting down to 18/6 or something similar. My plants stopped growing and I changed from 24/0 to 18/6 and growth started again. I also put the tiniest drop of superthrive in my bucket and the plants liked that. I'm also a noob though, so I could be way off base. Good luck.

Click to expand...

Nope, no root rot at all. In fact, the roots look super helathy!!! Very nice white, and very full.

I have superthrive, but don't want to use it yet until I know what's going on.

Thanks for the advice. you're not the first to mention changing light cycle....however, the person I got clones from runs 24/7 with no problems..

thanks again.

snut

A batch of mine did the same thing last run, it was a calcium deficiency.

I had tiny little yellow dot's with a brown spot in the center of the yellow dot's and I had a little bit of a tip burn going on. I also had no growth for about two weeks. I changed to just water with a PH 5.5 and ran it for 48 hours then I changed it again with PH 5.2 water then added my nut at half PPM and they took off by the end of week.

This is a REALLY old thread. I'm surprised that no one ever noticed what the real problem was. It's in plain sight right in my list of specs in the first message I posted. I wrote: Nutes, Flora Micro. That's all I was using, Flora Micro, without the Bloom or Gro. So of course my plants were dieing....They weren't getting half the nutes they needed, lol. A friend told me about the lucas formula, but told it to me incorrectly. Once I realized this, my plants began to thrive. I've learned a LOT since this thread was started.

Thanks to you all who replied. We can let this one die now.

-S