curling tips on seedlings

[jdflores07]

Hey guys! I'm a beginner here and I have a few questions and doubts about my week old plants.
About two days ago the tip ofthe leaves started to curl up. Not a lot of curling but I don't want it to progress and become a possible problem. The color seems fine and no bugs are in site. I was afraid it could be heat stress but the room is nice and chill. The bulb was 60cm away at first and my plants seemed to be streaching so I lowered the bulb to 50cm.

The lady's are a week old.
Watered with filtered water every 2 days or so.
Sitting in 5lt jugs.
Using normal soil with a bit of mix w/ vermiculite and perlite.
No nutes added yet (too young) All under a 400w hps 50cm away
In a 75 degree fanned room
Growing 18 with light, resting for 6.
Don't know the genetics of seeds, they were a gift.

This is what they look like:

Any advice would be much appreciated!

[Toker1]

Need more pearlite in the soil.

[jdflores07]

Do you think that would solve the curling up problem? I'm curious as to why a lack of pearlite would result in the leaves curling up. The soil has a bit but I could add more

[Toker1]

Yes, improper drainage can lead to leaf curling. Mostly leaf curling has to do with the plant receiving too much light, water, or heat. Improper draining can lead to overwatering/stagnant water. This can cause leaf curl, but could be the other factors as well. Since temps seem to be good at 75F (although you didn’t mention if this was at the canopy level or not), and I assume light hanging distance is good (no mention of this either). And I assume RH is good (usually at 75F it’s not too dry) so by process of elimination, my guess is it’s the watering issue.

[jdflores07]

Bought some pearlite. I'm gonna mix it in today. I think the problem could also be not enough humidity. The room is pretty dry and I have a fan blowing at them 24/7. Either way pearlite should sold the problem whether it's drainage or humidity. Thanks for the tip! I'll keep you posted mate

[Toker1]

Do it at next transplant. And humidity needs to be high for small juvenile plants.