I just got a few Rhodactis indosinensis and i hear that they like a little more water flow and lighting then your normal Actinodiscus. My question is exactly how much water flow should i be providing to these little guys. I have a small power head near them but its not doing such a great job, on the other hand i don't wanna blow them clean off the rock. Also i have them fairly high up in the tank for lighting reasons.