Seedling tips curling up

I am not sure if this is a sign of something that might be wrong. Leaf tips are slightly curled up. Temperature is between 22-26C. Watering about 150ml when the pot feels light with no nutes, but some nutes might remain on soil from my previous grow. There are some root remains on the soil also from previous grow, I usually leave them there. Humidity swings between 38% and 58% (can't do any better in this regard since it is very dry here). Is there something that might be wrong?

S


This is another one with the same curled up leaves.

Looks to be a little light stress..

Light stress or windburn from the dry air is my best guess based on those pics. What light are you running and do you know the ppfd or lux the plants are getting? Also, do you have a fan blowing right on them or really close to them?

FirstCavApache64 said:

Light stress or windburn from the dry air is my best guess based on those pics. What light are you running and do you know the ppfd or lux the plants are getting? Also, do you have a fan blowing right on them or really close to them?

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Running a 315W CMH at about 40cm distance, not sure about the lux. I do have a oscillating fan but it is about 60-70cm afar. I reduced the intensity to the lowest setting possible. Thanks.

It's good to give them some air movement but if you're on the dry side humidity wise, blowing directly on them can cause some minor leaf issues. You can try the App store for light Apps that measure lux. I've heard some guys have good luck with the Photone App but it depends on your phone it seems. I just broke down and bought a cheap Lux meter this grow and it's nice having some concrete numbers to make lighting decisions with.

Low humidity makes it hard for them to do their thing without absorbing too much nutrients.

It may help for low humidity but you can try

If you have a water mister bottle, just spray some water on the tent walls and do up all the zips.
Hang a damp towel in the tent.
Buy a humidifier