[2455coop]

Generally speaking you need a pump that can move the water in the top tank at least twice an hour ( I actually think 3 times is better). Don't forget to calculate the head pressure of ur pump. It usually says on the box. My pump is an internal...meaning it sits in the sump. And I have never had problems with it.

Remember if you have Central and South American cichlids...its best to have all 3 types of filteration. Biological, Mechanical, and Chemical.

An overflow will not get the waste that settles on the bottom. you will need a tank vacuum to remove that type of waste.

If it's a big tank...Get a breeding pair of Jags........or a Red Devil...lol...but don't add anything else