New to Rockwool. Why are These Plants looking So-so?

Trying to get the hang of rockwool and not sure what I'm doing wrong, please advise if you know rockwool well.

These plants were happy and well rooted into their upper 3" rockwool cubes, but since placing them on top of their lower 4" cubes some have taken well to it while most are a bit droopy and yellowish. Some have rooted into the 4" cubes while some the weaker ones haven't. They've been getting a few ebb&flow cycles per day half way up the 4" cubes(tray isn't deep enough to flood to the upper cubes).

So I'm wondering do they need more or less? Do I top feed them to keep water flowing through the upper cubes, or stop watering altogether for a while and wait for roots to reach through the 4" cubes? Are they over-watered? I hear people say it's hard to over-water rockwool, and my tray drains fully after every cycle, but they are droopy which I assume means too wet. Just don't want to do more of what's hurting them.....

Thanks!

I'll bet you a giant joint, that your ph-value is off

Those cubes look soaked man, ease up. Your watering to often for the size of the plants IMO.

Whats the ppm and ph? Cuz they look like they need to be feed. I've grow in all rock wool absorbent and water by hand from the top letting it dry out between watering just like dirt till the pot is lighter. Its harder to over water still I would let it dry out some. I like water from top it more like nature so it flushes out the block or whatever so you don't have salt build up..

jimmygreenfingers said:

Those cubes look soaked man, ease up. Your watering to often for the size of the plants IMO.

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Agree - could be overwatering

A few times a day for how long? Also how is your ph and ppm, looks a bit rich.

They look fine I'd just start to give them some cal mag. and YES you can overwater RW

Yup probably too wet. I keep pH about 5.8, ppm around 800, GH flora's in RO water, ebb&flow cycle happens pretty quick, filled and drained within 10 minutes. I've stopped watering for a bit to see if they get better. I'm just not experienced with this medium, figure it must work well since so many use it, seems handy to use cubes instead of loose media, hope I can get the hang of it.....

800 - i think that's way too much. my guess is nutrient lockout due to toxicity.

Nah it doesn't look like salts build up just like a mg def

you should cover your blocks. algae is growing bro. no bien