What am I doing wrong? Help!

I have three CBD Auto-Flower Compassion Lime seedlings growing indoors in soil. The seedlings are on day 10 and 9 since they popped from the soil. Yesterday, the first set of leaves on last of the girls to pop, showed browning on the edges and they are now curling inward. See images below. I’m new to auto-flowering plants and want to know what I could be doing wrong.


Full details:

3 x CBD auto Compassion Lime from Dutch Passion Seed Company
Grown Indoors
Each in a 5 gallon fabric pot
Seeds popped on the 8th and 9th June
Soil: recommended by specialist outlet - Plagron Light mix, which according to their specs, is a mix of the very best, carefully selected types of peat with the addition of various types of fibre and perlite.
Fed only water which has been left standing overnight to get rid of chlorine and pH corrected to between 6.2 and 6.5
Light: 2x Kosheal 600w led grow lights and 5 x 24w CFl daylight lamps
Temperature: varies between 19 and 26 degrees Celsius
Humidity: Low 60s with lights off, mid 40s - low 50s with lights on
Nutrients: None added yet - not sure when to start.

I forgot to mention that the lights are on VEG.
At what stage should I switch to BLOOM and when and what nutrients to use?

The actual power draw on Kosheal 600w led grow light is 100watt per the seller's description on Amazon. Recommended height above plants is 24".

What height do you have the lights above rhe plants? It could be light stress. Baby seedlings are very sensitive to light intensity. Otherwise they look healthy. The newest set of leaves that are forming look good. I would let them go as they are, and if the newest set of leaves look like they're stressing, I would raise the light away from the plants a little.

Is it just the one thats curling? I wouldnt worry too much, ive had plants where the first leaves looked misshapen and mongy like yours but the next leaves are fine and the plants grows as normal.

@Tracker: I think you could be correct about light stress so I raised the lights about 6" The new growth appears to be fine. At what stage should I start adding nutrients? When I bought the soil I also bought some cal-mag which from reading I see is a popular addition but reluctant to use it without guidance on when and how much.

@shiva71: 2 of the 3 are curling up but otherwise seem fine and are noticeably growing taller. Your post did ease my concern some, cheers

shiva71 said:

Is it just the one thats curling? I wouldnt worry too much, ive had plants where the first leaves looked misshapen and mongy like yours but the next leaves are fine and the plants grows as normal.

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This

stunk said:

@Tracker: When I bought the soil I also bought some cal-mag which from reading I see is a popular addition but reluctant to use it without guidance on when and how much.

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If your soil mix does not have any nutrients amended into it, then you should go ahead and start adding nutrients at reduced strength. Seedlings can be damaged if you give them full strength nutes, so be conservative with the nutes on the babies. Once they get a couple sets of fan leaves and start growing more vigorously, then increase to full strength on the nutes.

If you are using tap water, then you should already have some CalMag in the water, so supplementing with CalMag is not absolutely required. Also, take note of what's already in the nutrients you are using. Since I use tap water that has 120ppm out of tap, my nutes already have CalMag in them, the Calcium in the CalMag supplememt comes as Calcium Nitrate, and I don't want to overdose any of those three nutrients, i apply half strength dose of CalMag.

Thanks Tracker, was not aware there were traces of Calcium and Magnesium in tap water.