Burned seedlings with 8 Bulb 4' T5 setup (?)

Second grow, this time I got the 8 bulb 4' t5 setup from discount hydro. I kept the light 2 inches from the seedlings, 24/0, and have a fan blowing on them. Temps at the lip of the seedling cup (sunleaves digital outdoor humidity/temp thing) is ranging anywhere from 72-80 degrees.

Today I felt some leaves cause most of them are drooping hard, and one of them had leaves that were CRISPY at edges around the tips. Another one is twisting its leaves around pretty crazy.

I have no idea what the proper height for this lighting setup from the canopy is

Please help

Yer lights dont sound too close, especially w/those temps. Hows yer waterin situation? I'd pull the light back to about 8" away fer a lil bit and see if that helps

deftones420 said:

Second grow, this time I got the 8 bulb 4' t5 setup from discount hydro. I kept the light 2 inches from the seedlings, 24/0, and have a fan blowing on them. Temps at the lip of the seedling cup (sunleaves digital outdoor humidity/temp thing) is ranging anywhere from 72-80 degrees.

Today I felt some leaves cause most of them are drooping hard, and one of them had leaves that were CRISPY at edges around the tips. Another one is twisting its leaves around pretty crazy.

I have no idea what the proper height for this lighting setup from the canopy is

Please help

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As long as the temperature isn't to high there shouldn't be any problems. Depending on what you're growing in the soil might be catching a lot of light and heating up which wouldn't show on your thermometer.

I use a 4 bulb t5 setup and keep it pretty close. I think mine was actually about 6 inches away when they first popped. Try moving the light up to 4-6 inches and just leave it there until the plants are about to touch it. Once they get up there you can keep the light within an inch. I have a fan blowing across mine and the leaves never burn unless I forget and they end up actually touching the bulbs.

These popped on the 18th, and I think I over watered once at the beginning cause I did not check with the moisture meter. This is what I believed the drooping was, however I don't think it explains the crispyness. I also let them dry out, checked with moisture meter and watered them yesterday morning. They look same/worse. I do recall feeling some warmth on the soil like the other guy suggested...

Where in the hell am I? said:

Yer lights dont sound too close, especially w/those temps. Hows yer waterin situation? I'd pull the light back to about 8" away fer a lil bit and see if that helps

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Im thinking its hot soil =( . Im getting new beans on the way because of this, since these are supposed to be clone plants for a perpetual... damn. Will try 6" next time, ty.

Anyone else have additional insight?

mj320002 said:

As long as the temperature isn't to high there shouldn't be any problems. Depending on what you're growing in the soil might be catching a lot of light and heating up which wouldn't show on your thermometer.

I use a 4 bulb t5 setup and keep it pretty close. I think mine was actually about 6 inches away when they first popped. Try moving the light up to 4-6 inches and just leave it there until the plants are about to touch it. Once they get up there you can keep the light within an inch. I have a fan blowing across mine and the leaves never burn unless I forget and they end up actually touching the bulbs.

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If they're not dead don't get rid of them yet. Just move the light and see if they get better.

yeah im keeping them, they will go to flower. I've heard enough about burning/high stress problems early on causing low yields later on enough to want to get new beans tho.

This one was 30% indica, and I kinda wanted to get someting 80% indica anyways =)

mj320002 said:

If they're not dead don't get rid of them yet. Just move the light and see if they get better.

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nigga dnt throw em away!!wrap amluminum foil over the soil....flush the plant with DISTILLED phed water (6.5ph)

this prevnts light hitting the medium,which isnt to favoruble anyways....dude dont toss em..

juicyjayz said:

nigga dnt throw em away!!wrap amluminum foil over the soil....this prevnts light hitting the medium,which isnt to favoruble anyways....dude dont toss em..

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as juicy says, covering the soil will help immensely. I wouldn't cover with aluminum foil, as it tends to focus beams of light and could burn holes in your already-struggling leaves. Use mylar if you've got it, or even just white cardboard box cut to the size of your pots with a slit to fit around the base of the stem.

this is also important if you plan on supplementing with UVB light--one factor affecting root growth is UVB exposure. A gene in roots called RUS1 detects the levels of UVB and tells the plant to grow accordingly--high UVB=less growth, low UVB=more growth. UVB is toxic for the plant, so be careful how much you use, but it will help produce more resin during flower.

so covering your soil will help keep temps down and uvb out! win-win!

~JG

So the seedlings I spoke about in this post got so bad that I decided to toss em. It wasnt a bad decision, we all know when we stress the fuck out of a plant, they can turn out super shitty, ive seen it myself (buddy's plants).

I tried again with the light higher, and got the exact same results. I really doubt it was heating the soil this time around. Heres some pics. I am now leaning more heavily on over-watering, since I found out my moisture meter doesnt work anymore and the significantly lower heat these lights put off (im used to hid)






Can anyone confirm overwatering based on looking at these pics of the seedlings?

Forgot to mention, these are old, and these seedlings got just as bad as the other ones, even though the light was raised much higher. These are gone, and im now growing under my 400w mh cause I just cant afford to keep losing the crop. Im growing a bunch of shwag seeds to do some testing under the fluoro t5, but would still like to see if anyone can verify signs of moisture issues in the above pics.

i get by with a little help from my [forum]friends

I can't verify over watering but I can tell you I've grown many seedlings under t5's and never lost a single one. The soil does look a little moist and some of those plants looked a little droopy so over watering is a definite possibility. Maybe the soil doesn't dry out as fast under the t5's like your used to with hid's causing you to over water. I don't know but I guarantee it's not the lights themselves killing the plants.

deftones420 said:

i get by with a little help from my [forum]friends

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I have the same fucking problem with my seedlings under my T5HO. I can't for the life of me figure out what could be wrong with my seeldings. Everything seems fine, doing it the same way I always done it, only difference is my 6 lamp T5HO light fixture instead of HID.

I was just searching around ebay for a lens for my 400w reflector so I can air cool it and use it instead. I just don't understand why my plants are like burning up and dying. One guy said to move the light up to 20 inches!

If I see any more burning I'm going to have to do that.