Can someone help me figure out whats wrong?

[Gelato]

Something seems off about my plants. the leaves are not straight; rather it seems slightly curved downwards as if it were about to begin cupping.

 

[Green75]

Just looks like they need watered...

 

[insomniaczzz]

Very large and healthy looking plants. I agree with green, they look like they need watered. Will you be flipping the switch to flower soon? They look like they are just bursting to bloom.

 

[Karlee]

It looks like a DWC type grow so if it's a water problem you better figure it out fast , do you have air-stones a pump in the res? check on all your lines if you have air going to them.