How to start salad crops?

[Cameron Smith]

Hello...I'm new to aquaponics. I have a pretty good grasp on the basics...i have a small tank that is nearly cycled and i have a few flowers transplanted and a cucumber sprout looking very hardy and proud. I have lost several herbs and lettuce seeds. I planted them two inches deep to get them watered every cycle. I even sprouted them before planting them, but after more than ten days they have not surfaced.

What is the right way to start salad crops?

[Verna Gross]

I'm using rock wool cubes. Anyone have opinion on it