Hob External Filters?

[Mikey1]

I think I will do that then, dI I have to have a powerful air pump or will any be ok, and do they just sit on top the gravel, and the base buried?

any air pump should do if your only having one of them.....most sponge filters like that have weighted bases to hold the filter down on the bottom of the tank, so it will stay down even if not buried in gravel, but you can bury the base if you like.....i use them in tanks with no substrate at all, and the weighted base holds it down, so it wont float up

 

[khial]

simple then, will order one later, thanks for all the help