1000W MH Causing Yellowing/drooping of seedlings.

[clp]

Whats good Ic?

I recently put my 1.5 week old seedlings under my 1000W MH after being under the fluoro's for the start of their life. After a day they started to yellow and wilt a little bit, progressively this got worse. We have now taken them out, transplanted them into a different medium/grow bags, and put them back under the fluorescent. They have now started to green back up and are returning to normal.

I also put my Original Haze X skunk #1's under the MH after about a week of veg under the FL's. They are now starting to yellow and wilt a little bit too. We have taken them out and put them back under the fl's until we can figure this out..

Any idea why the light is causing this to happen? Are the seedlings just not strong enough for that much light?
My assumption/reading has shown me that as long as temperatures and humidity are controlled I should be able to grow these NOW under the 1000W mh. Our temps are constant at around 80 deg and our humidity is in check.
I really want to get them under the MH ASAP to promote more growth faster but this yellowing is a real problem..

Any help on this IC?
Need to figure it out ASAP


CLP

 

[cobain420]

How far away did you have seedlings from the light?

The switch from flouro's to a 1000W is a BIG change.

Did you have adequate ventilation?

I would try to re-introduce them if you have the temps in check, keep a safe distance, since you have been having trouble, I would start with a couple feet between the tops of the plants and the light, you can always move it closer.

Also what size containers are they in? You may want to water them right before sticking them under the 1K, and figure out how often you need to water.

Good luck with everything!

Whats good Ic?

I recently put my 1.5 week old seedlings under my 1000W MH after being under the fluoro's for the start of their life. After a day they started to yellow and wilt a little bit, progressively this got worse. We have now taken them out, transplanted them into a different medium/grow bags, and put them back under the fluorescent. They have now started to green back up and are returning to normal.

I also put my Original Haze X skunk #1's under the MH after about a week of veg under the FL's. They are now starting to yellow and wilt a little bit too. We have taken them out and put them back under the fl's until we can figure this out..

Any idea why the light is causing this to happen? Are the seedlings just not strong enough for that much light?
My assumption/reading has shown me that as long as temperatures and humidity are controlled I should be able to grow these NOW under the 1000W mh. Our temps are constant at around 80 deg and our humidity is in check.
I really want to get them under the MH ASAP to promote more growth faster but this yellowing is a real problem..

Any help on this IC?
Need to figure it out ASAP


CLP

 

[Daffy]

The roots weren't developed enough to supply the plant so the extra chemical energy was basically stressing the plant to death and bleaching its leaves since it couldn't produce clorophyll fast enough. Thats my diagnosis even though I don't know anything about the size, how far you had the light away(only a few high altitude places at around noon during the summer solstice have 90000 lumens, the plants growth is retarded past 50000 lumens). You would be fine if you kept the plant 3+' away from the light.

 

[Daffy]

You had them under the CFLs 24/7 then you tried 24/7 HID is that about right? The roots grow faster during the night when the plant's moving the sugars around so not enough time for them to grow since the plant was spending majority of its energy producing above ground tissue. The weak solution you were using on the plants probably was making them nutrient deficient too because some nutrients take more time to move through the vascular system, i.e. immobile nutrients.

 

[Daffy]

-

 

[mrred]

When youre hardening a plant to harse conditions, its best to watch them closely so you can take them out of those conditions before they get beat half to death.

 

[Lazyman]

My guess is the extra heat and light caused you to water more often to keep them from wilting, so they were getting more water than food. If you increase one thing you typically have to increase several others. Sounds like you've got it under control now though, good work.

 

[Frozenguy]

You got them used to the fluoros.

I'm 95% sure you could of put those seedlings under the 1000w MH immediately after germ and they would of been fine.
Seedlings outdoors have an intensity of about 1300watts/sq meter. How big is the footprint your light makes? Seedlings can take a bunch of light unless they are used to something with a low intensity.

Under normal conditions, seedlings can take full sun.

 

[clp]

How far away did you have seedlings from the light?

The switch from flouro's to a 1000W is a BIG change.

Did you have adequate ventilation?

I would try to re-introduce them if you have the temps in check, keep a safe distance, since you have been having trouble, I would start with a couple feet between the tops of the plants and the light, you can always move it closer.

Also what size containers are they in? You may want to water them right before sticking them under the 1K, and figure out how often you need to water.

Good luck with everything!

I definetly have adequate ventilation. Big 450 CFM fan cooling the hood and a canfan+CF setup venting the room.

I'm going to re-introduce them in the next couple days after they green up a little bit more under the fluoro's. They are looking better though.

I think the problem may have been that we had the light too close. We had it at around 19 inches from the plant, this is far enough away that I couldn't feel any heat from the plant but I feel that it was still too close.

I have them in 1/2 G grow bags now, after the transplant and will water them first
thanks!

The roots weren't developed enough to supply the plant so the extra chemical energy was basically stressing the plant to death and bleaching its leaves since it couldn't produce clorophyll fast enough. Thats my diagnosis even though I don't know anything about the size, how far you had the light away(only a few high altitude places at around noon during the summer solstice have 90000 lumens, the plants growth is retarded past 50000 lumens). You would be fine if you kept the plant 3+' away from the light.

You had them under the CFLs 24/7 then you tried 24/7 HID is that about right? The roots grow faster during the night when the plant's moving the sugars around so not enough time for them to grow since the plant was spending majority of its energy producing above ground tissue. The weak solution you were using on the plants probably was making them nutrient deficient too because some nutrients take more time to move through the vascular system, i.e. immobile nutrients.

I was not using any nutes. Only the FFLW soil. This should provide enough nutrition combined with the cotelydon's for the first few weeks of growth. Does this mean I should include some dark cycle for more roots? I've heard 24/7 is best.

When youre hardening a plant to harse conditions, its best to watch them closely so you can take them out of those conditions before they get beat half to death.

I realize that
My beginner mind though that the yellowing in the beginning may have been strain specific, I can't check them every day so when I came back they were pulled out.

My guess is the extra heat and light caused you to water more often to keep them from wilting, so they were getting more water than food. If you increase one thing you typically have to increase several others. Sounds like you've got it under control now though, good work.

It's true the extra heat and light do cause more frequent watering but this makes sense in my head. The light would cause higher heat and slight evaporation of the soil so we would need to water more frequently. We still only watered once they were completely dry or very close. Using the lift method and moisture meter.

You got them used to the fluoros.

I'm 95% sure you could of put those seedlings under the 1000w MH immediately after germ and they would of been fine.
Seedlings outdoors have an intensity of about 1300watts/sq meter. How big is the footprint your light makes? Seedlings can take a bunch of light unless they are used to something with a low intensity.

Under normal conditions, seedlings can take full sun.

Yea I think we may have but it's so much easier and foolproof to start them under fluoro's. We wanted to go the safest route and not burn the babies.
We have a 1000W in a 25 sq foot area
This thing basically looks like the sun but I think you are right about them being shocked in the change of light.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Thanks everyone for the help on this. I believe we have it more under control but I will update if anything changes or gets worse.

You guys here on IC are awesome

CLP

 

[Smoking Now]

Well seems like you figured things out, good luck!

 

[billboOG]

you must harden off new seedlings to the more intense light. move them to the side of the footprint of the 1k for a few days before into to the intensity of the 1k. I'm positive of this anwer after many years of going from floros to the big gun. move them out of the direct foot print, moving them in a bit litttle by little . they will tell you by the growth if it is too fast. yelowing drooping is a sure sinf that they have not adjusted.

billbo

 

[clp]

Thanks a ton! I'll try that also but its a little bit hard in a restrictive tent with this big of a light. The footprint takes up the whole tent pretty well

We have put the light 3+ feet away though so hopefully that helps as well

you must harden off new seedlings to the more intense light. move them to the side of the footprint of the 1k for a few days before into to the intensity of the 1k. I'm positive of this anwer after many years of going from floros to the big gun. move them out of the direct foot print, moving them in a bit litttle by little . they will tell you by the growth if it is too fast. yelowing drooping is a sure sinf that they have not adjusted.

billbo

 

[billboOG]

if you have a restrective area, move the light up as far as 6ft. The key is to get them adjusted to the more intense light. trust me they will adjust just fine if given a bit more light a day. 3ft is still too close

 

[Daffy]

clp, I have my one week seedlings(two sets leaves) 3 ft away, under 3 400 w. They are fine I could shade them with other plants but I don't have too. Here's problem like lazy man said, the plants nutrient uptake still matched the light of the fluoros, then there was a shortage of nutrients while using the HID. So yes I do advocate first starting the seeds under less intense HID light at 18hrs(equator at summer solstice) then after about a week bump it up to 21:30-24:00(the arctic circle-northpole on the summer solstice). Or 12/12 from seed. Too much light will retard growth because there will be a shortage of nutrients, mainly micro-nutrients(will deform your plant). Be strategic, pump the root system up, wait for the cells to divide and tissue to gradually built, then you can have a quicker start like you're after or if you're like me just let them grow slowly in the flowering room for the last 4 weeks which isn't going to waste any space when the lights go off at 6am I put them on the floor by a south facing window. Sunlight is the best light, they grow fast, and the sunlight prepares them for HIDs. You could veg under floros and sunlight even. That's how they veg in Mexico during the winter.

 

[clp]

if you have a restrective area, move the light up as far as 6ft. The key is to get them adjusted to the more intense light. trust me they will adjust just fine if given a bit more light a day. 3ft is still too close

I think we have it 4+ feet now. I believe as high as it will go in the tent. We may shade them too if we feel its not enough!

clp, I have my one week seedlings(two sets leaves) 3 ft away, under 3 400 w. They are fine I could shade them with other plants but I don't have too. Here's problem like lazy man said, the plants nutrient uptake still matched the light of the fluoros, then there was a shortage of nutrients while using the HID. So yes I do advocate first starting the seeds under less intense HID light at 18hrs(equator at summer solstice) then after about a week bump it up to 21:30-24:00(the arctic circle-northpole on the summer solstice). Or 12/12 from seed. Too much light will retard growth because there will be a shortage of nutrients, mainly micro-nutrients(will deform your plant). Be strategic, pump the root system up, wait for the cells to divide and tissue to gradually built, then you can have a quicker start like you're after or if you're like me just let them grow slowly in the flowering room for the last 4 weeks which isn't going to waste any space when the lights go off at 6am I put them on the floor by a south facing window. Sunlight is the best light, they grow fast, and the sunlight prepares them for HIDs. You could veg under floros and sunlight even. That's how they veg in Mexico during the winter.

Thanks for the help Daffy!
+ Rep to you

I want the fastest possible growth for veg, we are going with the shortest possible veg due to time constraints so which would be better?
18/6 or just keep it at 24/0?
We will probably be flippin to 12/12 in a week or so. We just want the mandala's to heal up a bit more.

Sunlight is not an option here, this is a large stealth grow in a neighborhood.