DWC leaves droping

Greetings!

my seedlings are 3 weeks old ( from seed )

After what i believed was a nute burn, (ppm was going from 250 to like over 800!! with an increasing ph from 5.8 to 6.8 in 24 hours) I changed the reservoir for only water ( 125 ppm ). the first set of leaves had their tips become dark and then yellow with an upward curling.

Now after a couple of days of just water, the second set of leaves are starting to drop down a bit. Not a lot but enough to make me believe there is a deficiency somewhere. The leaves drop a tiny bit day after days. Either overwatering or maybe lack of nutrient i guess... I believe I should start giving it nutrients since there is only like 50ppm of calcium and around 30ppm of magnesium in the water i'm using. And also the ppm started to drop instead of increasing.

here's a litle more details of the setup:

small DWC cabinet grow
2 x 200w (45w) CFLs
water temp at around 70 degrees
water ph being maintained at 5.8
inside cabinet temp at around 76-78 degrees
humidity between 30 and 40%
pots are half an inch over the water so only bubbles touches the bottom of the pots


So, looking at those pictures, do you see something wrong? thanks in advance

Hmm...I've not popped in a seedling at 3 weeks. Perhaps you know what you did incorrectly? I am trying to get beyond my one self on this one. Over feeding.

So, I agree, nute burn. I take 9 week clones and use only Cloenex and Excalubur, Ben Tea, and Rhzotonic. And starting with RO water those get me to about 120 ppm.

And this last time I went up to 360 by the 3rd week and withdrew the rooting supports listed above and the root system crashed on 4 out of 12.

And I banged the pH back and forth also.

So, do you know why the ppm went to 800? Gotta figure that out. One thing I'm learning is the roots are very sensitive in Hydro.

How to help this one? Well because of the browning on the top leaves. It may take a while. And it may be gone. I don't have much of a green thumb, but treating them like the babies they are, was good advice to me recently. When my setup was new, I did too much experimentation, maybe. But, we have to learn.

I go back and forth about a problem like this. Start all over? Well, if I had a mother plant.... Seeds take a while. Clones cost $14 each.

The only you can do now, I think, is just get her some rooting hormones maybe light Clonex in the water also, and no feeding nutes. Good luck....nice look sprout. Just got pushed to hard.

for the ppm drastic increase, i'm guessing the plants just drank a lot of H2O. but this problem decreased within a week. like 250 to 800 on day 1 then 250 to 600 on day 3 and 250 to 450 on day 5 let's say. It got better and better after i changed the reservoir for nute free water.

For the first set of leave tips turning yellow, i'm not very worried about it since the yellowish did not increase on the leaves. My only concern is the new real set of leaves curling down a little bit. It might be normal because of the weight of the leaf or like you said because they were pushed to hard at the beginning. So they are a little bit fragile.

Anyway, i'll send more pictures as the days goes by to monitor the changes

the other plant in the same bucket looks super healthy so I guess i should be fine