Overflow

Question
Does every tank require and overflow or to be drilled? My tank is tempered glass and cannot be drilled, and I was reading and came across overflow, im just curious if every tank has to have one of these. Thanks.

Answer
Hi again. You don't have to have an overflow on your tank unless you are planning on doing a sump style filter. Sump filters are typically used in a reef tank where you can set up a separate tank as a refugium. If you are planning to do a fish only tank it is not necessary to use this method of filtering. Some sumps are set up with a filter fiber of some sort, carbon and some form of biological filtration like bio-balls. This is fine however you can get the same filtration using a canister or hang on filter. I run all my tanks, even my reef tank simply using hang on and canister filters. It is nice to have a predrilled tank with an overflow but if your tank doesn't already have this then you may want to go with another type of filtration. There are a few filters out there that come with an overflow box that hang on the back and trickles down into a container that sits under your tank. These are made for those of us who do not have a predrilled tank to get the same kind of filtration. When deciding on a filter take into account the whole biology of keeping a saltwater tank. Don't go for the technology aspect. Do a little research on the plenum or deep sand bed which uses the naturally occurring good bacteria in your tank to help clean the water. These methods work far better than any technology out there and are very inexpensive to make. Most importantly remember that it is usually a good combination of different filtering techniques that will work the best. As long as you keep your stocking levels low, use only reverse osmosis or distilled water for filling up, top offs and partials, test your tank frequently, keep up on regular partial water changes, have good water circulation and utilize a very efficient protein skimmer, it really won't matter too much what filter you end up going with.