Seedlings have leaves with edges curled down

[presse55]

Hello

See my seedlings here on youtube http://youtu.be/5w6aReuWtM4

My questions:
- what can possibly explain leaves with edges curled down?
- are the healthier of these seedlings ready for the grow table?
- if not, how do I determine the right time to move them to the grow table?

Thanx a million in advance!

Ron
Montreal, Canada

[rainbowgardener]

Since no one has responded, I will jump in and at least that will bump your post so maybe someone else will see it.

I don't do hydro and don't know anything about it, but I do start tons of plants from seed every year under lights.

To start with you said seedlings with leaf edges curling over, but what you seemed to be showing was stems flopped over. Sometimes lettuce just does that-- it has a little bit of stem before the leaves start. If that stem gets too long, it can bend over. Growing in dirt, I just mound the dirt (actually potting soil) up around it. However the other possibility for seedlings that end up flopped over is damping off. It's a fungal condition that seedlings are vulnerable to in conditions of too much moisture and too little air circulation. You can read more about it by typing damping off into the Search the Forum Keyword Box. But in that case, by the time the plant is lying flat it is a goner. Damping off can be prevented, but not really cured.

But I don't know what the hydro folks do about that. Your set up with the seedlings down in the box and the rockwool staying wet all the time seems like creating perfect conditions for everything to get damped off. So hopefully someone who does hydro will come by and say a little more, or you can look it up else where.

Re the lights. When I am growing seedlings, I keep the lights just 2-3 inches above the seedlings and on 16 hrs a day. I don't know if growing in water instead of soil changes anything re the light requirements.l

[DoubleDogFarm]

Again not an expert on hydroponics.

If it was in a soil situation, I would lean towards,

Over watering root rot. "stress"
Not enough light "Leggy"
And maybe low nutrients. "Pale"

Eric

[rainbowgardener]

Any update on how the little lettuce plants are doing?

[presse55]

They're doing better, I think.

http://youtu.be/n1TNRz5vzyo

Questions:
1) The growth seems slow to me; am I right?
2) Will they do better with the GH "aggressive growth" nutrient ratios?

Any other comments are appreciated!

Ron

[Halfway]

What changes did you make since the onset of the problem?

[Burz]

I would definitely run the lights for at least 18 hours and no more than a foot above the plants.

[rainbowgardener]

I don't do hydroponics, but I do start tons of stuff from seed, indoors, under lights. I keep the lights no more than three inches above the seedlings, hung on chains so they can be raised as the plants grow.

[Burz]

Also consider the temperature in your growing area. If its too cold it will slow growth down quite a bit. Your plants didn't seem to be lacking nutrients from the video you posted so I would investigate your growing environment first. And like posted above if I'm using fluorescent lighting, they hang with adjustable chain/rope as close as I can get the bulbs to the canopy without burning them. H.I.D lighting you have to be more careful with, but still I prefer them as close as possible.

[presse55]

Thank you all for your comments.

See update at day 45: https://youtu.be/FPCZ5SdLkdQ

I've arranged for the lighting to be raised & lowered easily.

I keep the fluorescent bulbs around 3 to 5 inches from the leaves.

I run the lights 16 hours; temperature in that area is around 65F to 68F.

Other than minor browning at the edges of a few leaves, I'd say the plants are doing Okay.

Ron

[ElizabethB]

I am a soil gardener so take any comments with a bit of salt. Your plants appear to be crowded. A little too close for mature size. No experience with hydroponics jest general gardening. I usually allow 1 square foot for lettuce plants. Maybe 6" x 6" in a pinch. Less than that they are over crowded and will not produce well.

No research for you - just me.

[presse55]

I totally agree ElizabethB - that was definitely a beginner's mistake.

I'll know to space my plants out more in the future.

Thanx!

[ElizabethB]

OOPS - I miss spoke - 4 heads of lettuce per 1 square foot.

Sorry for the miss info.