Seedling dark green spots on leaves

[saavvy]

Hi everyone,

First time growing cannabis. Medium is coco coir. Growing indoors. I noticed my indica seedling starting to show dark green spots on leaves. This is what I have done so far


9/25 8:00 PM seed placed in glass filled with room temp water and allowed to sink to the bottom after a few hours by gently tapping. Ambient temp 21-25C, low light

9/26 11:30 AM seed did not “pop” but placed in 2 wet paper towel (soaked but not dripping) fold one third over the seed and the other third over that. Placed between two ceramic plates. Make sure plate does not contain excess water. Ambient temp 21-25 C , low light

9/28 seed that was germinated in the days prior placed 1” deep in reptile coco substrate that was hydrated with pH 6 DI water. Used solo cup as “pot”. Did not water because coco is wet/moist at this point.

10/1 seedling sprout breaks coco substrate.

10/4 2mL of pH 6 dH2O. Between 9/28 and 10/4 only light misting with pH 6 dH2O

10/7 40-50 mL dH2O

10/12 40-50 mL dH2O

been doing 18/6 for lights.
I noticed these spots in the last day or two. Have not given nutes and have not given cal mag. I wanted to wait until I transplanted to larger 5 gal pot to charge the coco with cal mag and use fox farms big bloom fertilizer (very low npk).I’ve been thinking it’s under watering as I’ve been very wary of overwatering(maybe to a fault). Any suggestions? I have attached pictures of my setup and the seedling

 

[Aussieaceae]

Time to start draining those cups each water / feed, if all you've been doing is using a spray bottle.

I agree with above. Choose a nutrient formulated for vegetative growth. I think Fox Farms is "Gro Big".

If you're worried about the npk value starting off, just dilute it more. Chances are the feed chart recommends too much. I always start at about twice the dilution the products recommend, and adjust as required.
Seedlings I'd say it'd be safe to dilute it further.

Start draining to waste.

Edit: also take it easy with the calmag, until you figure out how much the coco likes. Need to bare in mind the calmag will change your base nutrient values too. Especially true for seedlings > Less is nearly always more.

 

[saavvy]

Hey guys appreciate all tips. I watered till run off today with pH 6 water before work and gave the seedling nutrients from fox farms (0-0.x-0.x). When I came home the plant looked worse so I finally checked the ppm of the run off. 3000...lmfao
Moral of the story, if you’re buying coco that was made to be reptile substrate, rinse like all hell. I made the difficult decision to transplant into another solo cup with rinsed medium, ppm of runoff at 190. I’ll post one last time On this thread if the plants recover.

 

[Aussieaceae]

Yep. We've all been there.

Do your best to match your waste to your input with coco dtw and you'll love it.
Sounds like you already have things pretty figured out.

GL.

 

[Aussieaceae]

I wouldn't go past a little dolomite lime in your coco at transplant either. (After you rinse the hell out of it! )

 

[polishpollack]

Stick with roots soil.

 

[saavvy]

Hi all seedling has come a long way since it was burned in the reptile substrate coco. Since been transplanted in premium buffered coco 50/50 perlite And started on 1/3 strength veg nutes CNS17 from botanicare. Water everyday but give fertilizer every other day. light is 1000W led cob light approx 20-25 inches away. 45-50% humidity 20-23 C ambient temp. About a week ago I started noticing leaf edges curling and some dimples on the leaf

 

[saavvy]

Any ideas what could be wrong

 

[MrR.]

What is your humidity like in there?

 

[GeneBanker]

Can I just say I don’t like to see small plants so deep in a cup. It also looks like your second pictures plants are deep down in a pot. Are you watering too much per watering in a really big
Pot?

 

[saavvy]

Humidity is around 50%. Yes plant is pretty deep in the pot. The tap root developed with a weird loop that basically would not allow the plant to stand upright without burying that portion of the root and some of the stem. I have been increasing my watering amount. Initially I was watering about 1 L everyday but recently increased To About a gallon to try to get all the coco in the pot wet. The seedling is currently in a 5 gal pot and while I do admit that that is not ideal. I had to transplant it very early on due to initially planting in a terrible medium. Is this most likely root problems due to over watering? If so, would not watering for a few days be the solution?

 

[saavvy]

This is what it looked like a few weeks ago just to give an impression of how much stem is buried.

 

[MrR.]

Humidity is around 50%. Yes plant is pretty deep in the pot. The tap root developed with a weird loop that basically would not allow the plant to stand upright without burying that portion of the root and some of the stem. I have been increasing my watering amount. Initially I was watering about 1 L everyday but recently increased To About a gallon to try to get all the coco in the pot wet. The seedling is currently in a 5 gal pot and while I do admit that that is not ideal. I had to transplant it very early on due to initially planting in a terrible medium. Is this most likely root problems due to over watering? If so, would not watering for a few days be the solution?

You might want a bit more humidity 55 at least

 

[saavvy]

Update. Big plant in coco is the same plant earlier in this thread.

 

[Bsmoke78]

Time to start draining those cups each water / feed, if all you've been doing is using a spray bottle.

I agree with above. Choose a nutrient formulated for vegetative growth. I think Fox Farms is "Gro Big".

If you're worried about the npk value starting off, just dilute it more. Chances are the feed chart recommends too much. I always start at about twice the dilution the products recommend, and adjust as required.
Seedlings I'd say it'd be safe to dilute it further.

Start draining to waste.

Edit: also take it easy with the calmag, until you figure out how much the coco likes. Need to bare in mind the calmag will change your base nutrient values too. Especially true for seedlings > Less is nearly always more.

Any ideas what could be wrong

Yea looks hot