Ebb and flow problem...why are my plants turning yellow? (merged)

I see NO evidence of any pathogens in your system. In fact, that last pic shows very healthy plants!
I'd advise the following:
-Avoid allowing air-pruning to occur. Run Cannazyme if you see evidence of dead material in your root ball.
-Those wrapper things hold more moisture than you want and you might consider
'planting' the peeled cubes in a bed of hydroton next time.
-Drip-to-waste irrigation for rockwool is a good way to go. You can set the drip rate and timing to allow for drying between waterings.

Use a 'zyme product to clean your system. You don't have to replace the pump. If the hydro shop guy told you to do that, smack him! Lol! He's trying to get you to spend $$$$! Run the system with no plants, with a high dosage of peroxide. That's going to clear up bits of organic material that could rot.

You ever consider going to Hydroton in quart or even gallon pots in your flood n drain? It's MUCH more 'airy' than hydroton and you don't get that slow drying thing going on. Just a thought. The local hydro shop has a display of catnip, peppers, and some purple-leaved ornamental growing in just that arrangement. It's quite efficient, and for how dirty the whole thing is (dead leaves, muck, etc) all the plants are extremely healthy. Goes to show how resilient plants are when their roots get enough oxygen.

That deficiency appears to me to have been an iron def. Not bugs or viral.

My plants looked sorta like that in E&F because of both root rot and being root bound. I ended up switching to DWC. If your roots aren't sticking out of the cube, they should be. The roots have to be big to support a plant of that size. If not, they go to shit like you are experiencing. Took me three grows to figure out the problem, so don't feel bad.

You just need to get your timing right when feeding your plants. Like if you're running HIDs water 2-3 times a day. CFLs 2 times. 1 water in the morning and another watering 1 hour before lights go off. And if it gets really hot in the room you may need to water more often.

with straight rockwool you gonna run into a lot of problems like this, you could use pots filled with hydroton to give the roots some breathing room.

Hello all ...i had this same problem in my last grow...i have been doing everything by the book...as soon as i saw roots coming out the bottom on the 3x3 rock wool cube i put them in the pots added the rocks and set them up to flood and drain 3 times a day ...up until this point i was watering by hand2 times a day.... i put them in my ebb and flow ...this was Sunday evening ...by Monday night i could already see the new growth begin to turn yellow and some of the existing growth on the plants have also begun to yellow...its only Tuesday and they were perfect Sunday night ...i have scrubbed everything with bleach and disposed of everything that was replaceable...i thought i have kept them in the rockwool cubes too long last time (2 months) and they might have gotten root bound.... but they are just 3-4 inches tall and only 3 weeks old this time im so confused...what should i do ...??? :(

How about some photos and fill out the troubleshooting sticky at the top of the plant problems section?

And off the top....try watering twice a day like you did by hand and see if it makes a difference.

Ps....they're not in a hydrohut are they?

They are in a hydro hut ...why do you ask ...??[attachment=o187094]

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I have not allowed my plants to air prune and i put them in 3 gallon pots in my ebb and flow tray...and within 2 days they have started to turn yellow...they are 3 weeks old and 3-4 inches tall..[attachment=o187171]

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here is what they looked like Tuesday night ...they were only in the tent in the ebb and flow 24-30 hrs and they started to yellow...i switched from watering by hand 2 times a day in a tray to the ebb and flow Sunday at 6pm and they started turning yellow by Tuesday morning at 7am ...something just doesn't seem right ..if i had left them alone with no nutrients i don't believe they would have started to yellow so whats up ...?

i used to use the cheap grow rocks and my grows rocked.... i had 3 very successfully grows....since i have switched to the more expensive hydroton ( the little rounds balls) the problems started this is also the only thing that has changed...

Did you pre-soak the hydroton in pH 6 water until the pH remained stable after 24 hours? It comes from the factory at a pH above the range that hydro pot likes. You need to adjust it before use. Looks like something is locking out iron.

Did your last plants do great until you put them in the hydrohut? And then no matter what they turned yellow and died? And are these plants doing the same things?

IF that is true you need to get in touch with the people who make them.....there was an issue with some hydrohuts putting off toxic gasses or something.....hang on, let me see if I can find the link.