question about flood table

I'm building my own flood/drain system. I'm got the table and the lid and I've got 6x6x6 rockwool cubes. I'm not sure if I should put the cubes into net pots or if I should just sit them in the table? any advice

Just set them on the table.

Rockwool is ideal for drip systems. Invest in some hydroton or lava rock next time.