What filter should I get?

Sponge Filter

       Sponge filters are another popular choice. Mostly used in fry tanks or shrimp tanks. They use air pumps to power them and they aren't able to suck little fry up and won't push our fry or shrimp around the tank. They are also thecheapest on the list. "How?" you may ask. For example, say you gat a hang on the back filter for $6.99. You would also want some filter cartriges for it too. You are going to need to keep replacing the cartriges every month. After a few replacements, it will start piling up. with sponge filters, you only have to squeeze out the spong evry 1-2 weeks. Sure, after awhile you might have to get a new sponge but its a lot cheaper than other filters.