Filter for small tank?

[newfishguy]

I have a Whisper Power Filter that I am getting ready to put in my qt. I was going to use the same for my other small display tank but it says they are not recommended for use with aquariums that have sand on the bottom. Thats fine for my qt because it does not have sand on the bottom. However, what should I use for the other small display tank? Should I get a skimmer for the small display tank (15 gallons)? I like the small power filters though because they are inexpensive.

 

[mandfishes]

I don't know. But I'm glad you posted because I was going to get one of those kind of filters? Ive heard you can filter with live rock and a protien skimmer.