850gph too much for 20g?

[kim7]

I have 20g Long tank with 3 fish and just 2 xenia frags. I just put in my 850 Gph power head, it seems really powerful but not too powerful. I made it faced to the surface Would this be too much? this is the only power head i have in the tank.

 

[bobman]

If you sand is staying down and its not to violent on your coral then your good. Most powerheads dont actually put out what they say so I would assume you have about 30 times turnover give or take a little and thats a good number