Uh ho!

[slo-han]

I MAY HAVE GOT INTO A HURRY HERE! my clones are doing the canoe thing. they are under a led system w/ an agro tube supplement. I gave them some neuts also The lights were about 8 inches away. The leaves are curling up and looking burned - anyone know what I did or did not do?

[Katzie_Wolf71]

Might be heat stress or not enough air flow, you need figure what the temp is at the top of the canopy and nute burn perhaps but without a picture to see its a hard one to say. Check pH of your run off when you water them.

[thegreengrower]

Reasons why leaves curl up is heat stress.
Obviously there are many more, but primarily that will be where your problem is.

[Schmokin]

When leaves curl up it is to try and open the stoma on the bottom of the leaf to increase transpiration. Almost always a heat thing.