Light too close for seedlings?

Seedlings germinating from October 16th. Made a few errors in the beginning, such as putting them under my 400W LED veg light, gave them water with and without nutrients. After doing significantly more reading I’ve stopped watering them until I see the pots lose their moisture. I think I’m almost there but this morning, one of the girls is mildly curling its end leaves upward. Colour is still good, even, and similar to its neighborly plants.
Germinated in paper towels, using Solo cups in Coco/Perlite mix. Will eventually be transplanted into autopots, once a few extra leaves show up (is that right?). Lighting at the present is a 24W T5 18/6 cycle. Approx 4" away from leaves.

Is there something I should be doing to correct this response from them before I get a different problem?

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Nice job so far.

Do you have a digital pH meter and TDS/ppm meter to measure the water going into and out of the plant? Coco and perlite is going to drain and dry pretty quick. Your soil looks pretty dry in the pics.

I have not added any water since I’d been advised to tone down the aggressiveness when I initially watered them (every 2-3 days). Soil is progressively feeling dry, but I can feel very mild moisture (even negligible) at the tip of my fingers. My original plan was to water tonight or tomorrow, but I’ve stunned them enough that I was looking for confirmation before watering again.

If consensus is to water again, would I follow 1/2 strength of week 1 schedule from my nutrients at this point? You can see where I’d burnt the tips and trimmed them before from my mistake(s).

Tonight is day 6 without any tampering.

Hi - they look thirsty. I have plants that are very close in age. I ahve watered them to run off once so far. I lightly mist otherwise. The water you add to your plant should be 5.8pH, with or without nutrients added, in pure coco/perlite. This is important so that the nutrients in the soilless media are available to your plant. When you water, you want to add enough so that it runs through the solo cup about ~25% of the total water you add through the bottom of the cup.

1/2 dose is ok. I do 1/4, but there’s no right/wrong, you have to watch your plants. If it is in pure coco/perlite, it will need nutrients.

Digital pH and TDS meters are key to getting reads on your water and soil health.

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Excellent. Thank you for the quick reply. I can pH water to 5.8 no problem, and I’ll try 1/4 dose of nutrients. Watering to a return of 25% - I’ll do my best.

I’ll post return pH and TDS if I don’t mess it all up.

Thanks again!

Watered. pH 5.9, ppm 308, run off approx. 25%. Hopefully this does the trick. They do look more “tired” than when I’d taken the picture earlier today.

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After watering they will droop a bit as the water goes thru their veins. After a few hours or a day theyll be happy n perky again. Hows it go today?

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You are right. First pic shows a dark splotch …overwatering.

Watering daily is a good thing. But, only a little water.

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Got any recent pics?

When you say the ppm was 308, what were the ppms before you added nutrients? Next time you water, also measure the pH and ppm of your runoff. It help give an indication of your cocos condition.

Good evening @Sixpackdad and @PurpNGold74, @tanlover442 and others.
The ppms before adding nutrients from what I recalled was 80. I used distilled water and added the pH down to a 5.9. My runoff combined measured a ppm of around 360 and pH 6.1. I have read that it can give me good indicators to measure my runoff, so it is my plan to continue doing so.

Here they are tonight. Looking slightly yellow.


I am gonna say stay the course - 1/2 dose of nutrients, 5.8 pH, water to runoff, every 4 days (or sooner if the cup feels light).

And I’ll give a quick shout out to @raustin just to make sure I’m not sending you off the map.

Thank you. There’s so much out there that is contradicting. Hard to pick a direction sometimes. That’s why I really enjoy this site so far.


Everybody has an opinion. Choose wisely.

two things: 1-look like they need more nitrogen OR less water(slight yellowing leaves)
2-several are STRETCHING…Weak light OR too far away
cut pipe cleaners in half, make a loop around the stem, push the rest in the dirt
another week and it will not be needed.


Since I cannot see the bottom of the cups, let me ask a stupid question.

Do the cups have drainage holes???

Yes they do. About 20 holes done with soldering iron. Overwatering, even weekly? Can I fix a nitrogen deficiency by increasing ppm next feeding?
Thanks for the guidance!

I think these guys are ready for a transplant into bigger pots.


I just texted this to my wife. Pots are being delivered today. I look forward to adding light and decent pots.

Do I use pH water with transplant, or water with nutes?

Are you going to continue with a coco/perlite 50/50 medium? If so, yes, you should water & nute, and continue to pH to 5.8. Coco and perlite are basically void of nutrients.

Yes, staying with coco/perlite. Should I aim for 500ppm, or continue with ~300 to see how they react? They’re moving to autopots, LED under veg tonight if time permits.

I do 1/4 nutrients and watch my leaves. I recently had some very minor magnesium and potassium deficiencies, so I bumped up to half dose. The deificneices didn’t proceed and just yesterday I went back to 1/4 dose.

But I am using an amended coco soil. It’s got some nutrients added. You are going in pure coco/perlite, which is void of nutes. So I would consider going to half, maybe 3/4’s, for the initial watering of the new coco/perlite. I do not know much about auto-pots, but there may be a thread that gives more detail on how to initially set them up.

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