Too much light, LED, first indoor grow

[johnybologna]

I have some seedlings (1 week in) that are not doing great. As you can see in the picture, the leaves are crunchy and yellow on the outside, and dying off. I suspected too much light, so I moved the lamp from 20cm to 80cm distance 2 days ago. I'm not seeing any improvement. This might be because the plants need some time to recover, or maybe there's a problem that I'm missing. I have some experience growing outside, this is the first indoor grow. I have a 60cm x 120 cm grow tent, and a Bonzai 180W LED panel. Plants are auto White Widow. I'm growing in pure compost. I've never had problems with pure compost, but maybe it's too strong? If it is, what should I do to change the situation? Should I turn the intensity of the light down? Or should I just wait, assuming that increasing the LED-plant distance is sufficient?

 

[Listersmeghead]

I have some seedlings (1 week in) that are not doing great. As you can see in the picture, the leaves are crunchy and yellow on the outside, and dying off. I suspected too much light, so I moved the lamp from 20cm to 80cm distance 2 days ago. I'm not seeing any improvement. This might be because the plants need some time to recover, or maybe there's a problem that I'm missing. I have some experience growing outside, this is the first indoor grow. I have a 60cm x 120 cm grow tent, and a Bonzai 180W LED panel. Plants are auto White Widow. I'm growing in pure compost. I've never had problems with pure compost, but maybe it's too strong? If it is, what should I do to change the situation? Should I turn the intensity of the light down? Or should I just wait, assuming that increasing the LED-plant distance is sufficient?

Yeah, that looks a bit burnt, could be both lights and hot soil. Pictures in natural white light would be good to have a look at.

 

[Slicknick909]

Either nutrient burn or over-watered, hard to tell with the blurple light.

 

[johnybologna]

Yeah, that looks a bit burnt, could be both lights and hot soil. Pictures in natural white light would be good to have a look at.

 

[Slicknick909]

Looks waterlogged to me! The problem with pure compost is lack of aeration and drainage for the root system.

 

[Nunyabiz]

Yep that's flat zero aeration and the soil has gone anerobic. Also probably a bit to rich especially for autoflower seedlings
I would start over with totally different soil .
If you're using bottled nutrients then just use coco with 30% pumice and a little biochar.

 

[AdaminCO]

Generally pure compost is going to be too hot regardless for a seedling.
Get a bag of Happy Frog, seedling soil, or a Jiffy pod and try again.

 

[johnybologna]

Due to the quarantaine, I can't get the supplies I want... deliveries here are impossible
I tried fixing the issue by adding perlite I had lying around, but didn't work.
My local garden center finally reopened, so I can get some soil, but obviously, they don't have anything specifically for cannabis. Which soil should I get? I can mix in some pure compost or my compost/perlite mix. How much should I mix in? Or should I just wait until I can get deliveries again... might be at least another month.

 

[bud kushman]

Generally pure compost is going to be too hot regardless for a seedling.
Get a bag of Happy Frog, seedling soil, or a Jiffy pod and try again.

Happy frog will be too hot for the seedlings he should start them off in just peat moss or a seed starter, though I do agree with eventually using happy frog it is a good soil and I do use it myself, but I do add a little more perlite to happy frog, This current grow I am on I am actually going to use ocean forest soil. Same company different soil.
I think his problem mainly is the compost is also to hot, I don't know exactly how you would go about saving these plants. here is a pic of a current grow it is a 2 week old tangerine dream started in peat moss with a little bit and I do mean a little bit of happy frog mixed in. Good luck in your grows and wishing you lots of good buzzes!!!!

 

[AdaminCO]

Happy frog will be too hot for the seedlings he should start them off in just peat moss or a seed starter, though I do agree with eventually using happy frog it is a good soil and I do use it myself, but I do add a little more perlite to happy frog, This current grow I am on I am actually going to use ocean forest soil. Same company different soil.
I think his problem mainly is the compost is also to hot, I don't know exactly how you would go about saving these plants. here is a pic of a current grow it is a 2 week old tangerine dream started in peat moss with a little bit and I do mean a little bit of happy frog mixed in. Good luck in your grows and wishing you lots of good buzzes!!!!

Just a heads up, Happy Frog is actually what you want to use for seedlings. Fox Farm Ocean Forest is the one too hot for seedlings. I start off in Happy Frog, then switch when I transplant into 5 gallons.

 

[Canadadoes]

My local garden center finally reopened, so I can get some soil, but obviously, they don't have anything specifically for cannabis. Which soil should I get?

Do they carry Pro-mix?

 

[AdaminCO]

You just need to find a majority soil based mix with perlite, naturally buffered to 6.5ish.
Miracle grow organics (because everyone carries it) will be just fine, but Id recommend adding a bag of perlite to whatever you get.

 

[BigDannel]

Just a heads up, Happy Frog is actually what you want to use for seedlings. Fox Farm Ocean Forest is the one too hot for seedlings. I start off in Happy Frog, then switch when I transplant into 5 gallons.

I guess I've just been lucky using FFOF with seedlings, anything that showed a solid taproot before being planted has always done great for me. I may just have different strains that have coincidentally been able to handle it, I may grab some Happy Frog going forward just to be extra careful with other ones.

 

[SmokingWings]

@johnybologna, I plant stuff in pure, or close to pure, compost many times outside. It works. Bring the compost inside and try planting and problems start. I figure that inside is an artificial environment and plants start to react to the loss of pur sunlight, rain, breezes and wind and natural temperatures.

The compost works better inside if it has been diluted with peat moss, perlite, vermiculte, coco coir, or any of a number of other soil amendments. Certainly worth a try.

 

[johnybologna]

Same problem again! :S See pics.
I'm growing in soil for seedlings, with 30% perlite. Didn't overwater.
180W Bonzai LED panel.
Initially, they looked great (but seemed to grow very slowly). Then, the oldest leafs turn yellow and shrivel... These are over a month old!! :S
What am I doing wrong?

 

[ZoomZ06]

To me it could still be a soil issue. Yes there is perlite in that soil but there should be far more. This is a picture of one of my girls that are a couple weeks old. Notice how much perlite is in it. The way I look at a plant when it’s in it’s early stages of life, is to build the roots before building the plant. Have good aeration and drainage when using soil. With healthy roots come a healthy plant. Also in the 2nd picture it looks like the edges of the leaves have gone quite crispy. To me that would indicate an over watering issue. Are you using an auto flower strain? Those pots would be too large if they aren’t autos. I would try using a plastic solo cup to start in first to allow for a better root ball. I cut holes in the bottom of mine to allow for drainage. How are you watering these plants as they grow? When you plant the seed are you soaking the entire pot?

 

[Canadadoes]

Soil looks pretty damp, how much water have you been giving them? And at what pH?

 

[Nunyabiz]

Plant in a moist seedling mix and water only the seedling not the entire pot.
Your soil is probably a bit too hot.

 

[johnybologna]

No idea what the pH is ... don't have a meter.
I've been giving water very sparsely! Definitely not soaking the pot, giving minimal amount of drops every couple of days. Haven't watered in days ... so I don't understand how they are still wet. Obviously, if you have non-LED lamps, the heat causes evaporation. But I'm surprised at how slow this evaporates. The pots are small BTW: diameter of maybe 3 inches (7.5 cm)...
Yes, it's an autoflower.
The soil is a seedling mix :S So replant with more perlite? How much (%)?

I'm riddled really ... it seems that every diagnosis is impossible (overwatering: I hardly water; too hot soil: I use seedling mix; too large pots: pots are pretty minimal...)

 

[ZoomZ06]

Not knowing the Ph will be a huge factor. A plant can only uptake its nutrients within a certain Ph range. I know the water that comes out of my tap is at 7.1 which is far too high for plant uptake. Optimal range is between 6.3-6.8. What majority of people use is 6.5. I’ve left a chart here so you can see where each nutrient begins uptake at which ph range. If a plant can’t absorb nutrients it won’t uptake water. Every couple of days may even be too much. When my girls are young in solo cups their water can last 3 sometimes 4 days. Each strain is different and environment plays a factor for sure but I always found to be as patient as possible when it comes to watering