Seedlings have some kind of deficiency, but what? Help!

Hi

My seedlings are almost 1 month old. I grow indoors, hydroponic, e&f, rockwool. This is my very first grow.
At this point I am using Flora Micro and Flora Gro by General Hydroponics. My feed solution is 350 ppm, PH 5.6, RO water (with 7 ppm to begin with).

I overwatered the seedlings at the beginning, hence the brown tips on the bottom leaves and stunted initial growth.
After curing the overwatering issue, I got light green leaves which I fixed by adding more of the nitrogen rich Flora Micro.

At this time, some of the seedlings have yellow undertones to their leaves. Picture is attached.
I cannot figure out what I am doing wrong.
I thought nitrogen deficiency, zinc, manganese? None of the pictures I've seen seem to be exactly as mine.


Any advice?

Thank you!

It could be a slight manganese def, but it's still looking pretty healthy.

Keep an eye on the new growth. Also, how are your roots? Rock wool holds quite a bit of water so
managing the root zone moisture at this stage can be a bit tricky.

From your pic, the new growth appears to be healthy.

If it is available to you, I would recommend a mycorrhizae inoculant to help with root development.

Good luck!

Thank you for your responses.
I checked the roots. White and hairy under the plastic film that wraps the sides.

Meridith said:

Thank you for your responses.
I checked the roots. White and hairy under the plastic film that wraps the sides.

Click to expand...

Always a good sign!

I'm sorry but the leaves don't look so good. 350 ppm is to be used for the first week only. You say that you've been growing this for one month. Your ppm should be at least 750 and according to this chart, it should be even higher (which I think is too risky, but the chart says what it says). http://gh.growgh.com/docs/Feedcharts/GH_FloraSeries-REC_03216am.pdf
The chart also says to add more things but I think that risky too, or at least not very necessary. Just giving grow and micro of this fert isn't enough, if I understand you right. You should be giving some of the bloom fert too. I'd say raise the pH some as well, to 5.9 or six. Don't expect it to stay there but just try to maintain a zone like 5.8 to 6.4 perhaps. Keep a close eye on ppm and try to use that first to lower your pH if the pH goes up and ppm in the reservoir goes down. Then adjust with a pH adjuster if necessary. This is the first post I've ever seen where the grower says they're only using grow and micro, not the bloom. I've never used this fert but I think they're suppose to be used as all 3 together, unless you use just micro and bloom, the lucas deal. the idea there is the micro already has nitrogen in it. In the end, as long as plants get everything they should, they should be okay.

I saw the chart and it seems to be really confusing. They say week #1 id seedling, #2 is early growth, #3 is late growth. They send it to flowering after at week #4. It doesn't seem right to me. Maybe for those who do SOG it is acceptable.
My plants are grown from the seed. The first to weeks they had a super thin stem so that I was afraid to breath near them...
But, say, even if I cloned them and had thicker stems to begin with, then I would have to wait maybe a week or so until the roots come out. Right?
Then, say I want to train them so that I can make a scrog at flowering... This is another 4 weeks in growing at the very least. Maybe 5 for better yields...
Or I am out of my depth here? I realize my knowledge is theoretical.
I was following the chart according to the stages. As long as I considered the plant to be a seedling (but not the first week because it had nutrition from the endosperm), I gave it 300-350 ppm.
Then, after it gave me 3 pairs of leaves I increased the feed to 420 ppm and continue to gradually increase it almost every time.
But to be honest, the chart for the Flora series is very confusing and if you can suggest a better nutrition complex for the plants in hydro, ebb and flow, I would very much appreciate it.

Thank you for your comments.

You didn't say anything in your first post about raising the ppm. Take it too 900 but measure the ppm when mixing all three nutrients the way the chart says to use them. In other words. mix equal amounts of the three bottles evenly taking your ppm to 900. Your plants are old enough.