Filter placement?

[Colwell]

Hospital tank advice

I recent bought a 15 gallon tall aquarium and would like to use it for a hospital(quarantine) tank. What all do I need to have in this tank I have a AC 150 filter, a 50w heater, I have a air pump I can use if needed. It currently has gravel in it, should I remove this and keep it bare? This may be a silly question but, can I or should I add a few fish in there. I just don't want it to be bare and running all the time for no reason is all. But I know I can/could benifit from having it up and running if something were to go wrong. I currently have a 55g with 19 mbuna cichlids and a albino pleco. I also have a 45 gal that is pretty much empty, just changed the substrate to flourite as it is soon going to become a planted tank. Not too sure what kind of fish I want in there yet though. Any and all suggestions are greatly appreciated. If I do in fact have to keep it plain I know I'll be tempted to plant it or add fish or something lol

 

[Andrew McFadden]

I just use a sponge filter. In the mean time the sponge is in one of my other filers on my main tank. I drain water from my main tank to the other so the water matches perfect. add the fish and filter and your good to go for whatever. It's also a bare tank with a heater