Help!! White Widow sedling in last throws of life -((((

Help!! White Widow sedling in last throws of life -((((

[HR][/HR] 2 of my 5 new seedlings are looking VERY ill . In fact, I fear one is close to going up to that great big farm in the sky and leaving his 4 cousins behind. The facts:

Started with seed bank White Widow feminized some 3 weeks ago placed in wet rock wool under a 600W MH light. Everything looked GREAT for the first 2 weeks, so did something very stupid .

I had them in a plastic tray standing in about 1 inch of ph controlled water, which I changed out occasionally. Then I added about a small capful of nutes. I measured the tray water 2 days later with a PPM meter and saw it hit 2400 PPM – probably about 5X the recommended dose.

Did some more background research and realized that: 1) I was over watering and should never have left any standing water in the tray, 2) I nuked ‘em with way too strong nutes.

So, I flushed everything several times with ph controlled water. 3 of the 5 plants look GREAT. In 3 weeks, 1 is about to hit 5 inches and the other 2 are just under 4 inches. But, that last 2 look so so.

Center photo: 2 sick plants
Right: 1 VERY sick - necrosis and brown spots and yellowing
Left: 3 VERY strong plants

Questions:

Is there anything I can do for this last plant – looking all yellowed with necrosis and brown spots – or is it too late??

kind of curious why they in no other medium then small rock wool cubes?

They look hungry. Seedlings usually don't get feedings for a couple weeks in soil because they draw nutrients from it. That rockwool gives it zero nutritional value. If you plan to keep them that way, look up soiless medium grows to learn how to feed.

They will be ok once you decide to plant them in medium.

I dont do hydro, but IMO pitch them two, and germinate two more seeds! Feminized seed has been known to grow balls after being stressed like that.
Remember I don't know anything about hydro other than, almost 9 out of 10 pics I see are ugly, but the good ones are really good. good luck to you.

rootbound to the cube, got to do something with them asap. imho