questions on prop tank

[garvin90]

I'm setting up a 20gal long ricordea propogation tank and wanted to know about how much flow I should use and if a closed loop or just a powerhead would be fine.

Also should I use sand instead of BB to avoid any attaching to the glass?

 

[pledosophy]

In my 20g long mushroom prop tank I use crushed coral for substrate. That way new mushrooms can attach to the CC and I can then glue them to rocks.

My flow is around 10x.