Design Stage: Filtration Mechanism

Let us make a distinction between filtration mechanism and a filtration system. The mechanism deals with how you get water out of the tank into the filtration system and then back into the tank. It is a very thin line between the two. For this aquarium, the mechanism makes use of a sump tank housed beneath the main tank. A sump tank is basically a water containter that extends the overall volume of water in the aquarium and it usually also houses the filtration system. Water is draw from the aquarium via the natural force of gravity down into the sump and then pumped back into the aquarium so that it forms a water cycle. In the attached picture you can see how one hose draws water from the main tank into the sump under the table, and how the return pump pumps water via another hose back into the main tank.

Many people use glass sump tanks but for my case, I've chosen to use a plastic tub which cost $8.50. After all a sump tank is usually hidden out of sight so I felt that there is no need for an elaborate and signifcantly more expensive sump tank made of glass. A plstic tub will work just as well. However when it comes to newly purchased plastics, you have to be careful of the prescence of oil, odour which may be harmful to fishes. It is advisable to soak the tub for a couple of days.