leaves on hydroponic cannabis plant curl down and droop

[inspired333]

Water levels should be 1/2 in under the bottom of your net pots.

I know this thread is kinda old, but, isn't 1/2" under the bottom of the net pot a completely arbitrary guideline. If you're in a 10" net pot and have it full of media, your plant cube/roots could be anywhere from the very bottom of that net pot to the very top of it - and that's about 8 to 10 inches in difference.
If you try and grow a seedling with the water level a 1/2" below the bottom of the net pot "just because", then your plant could be 10" above the water level and will not be able to reach the water.

 

[dtowndabber]

I know this thread is kinda old, but, isn't 1/2" under the bottom of the net pot a completely arbitrary guideline. If you're in a 10" net pot and have it full of media, your plant cube/roots could be anywhere from the very bottom of that net pot to the very top of it - and that's about 8 to 10 inches in difference.
If you try and grow a seedling with the water level a 1/2" below the bottom of the net pot "just because", then your plant could be 10" above the water level and will not be able to reach the water.

Don't use 10" net pots unless the diameter of what you are growing is going to be 8"