What is the Best Location for a Tropical Fish Aquarium Pump?

It is usually advisable to have the pump at a higher level than the tank. This will prevent any possibility of a siphoning action draining the water from the tank back into the pump. Pump platforms are available for pump placement. These are small plastic or metal shelves designed to hold the pump while hanging on the back of a tank.

If it is desirable to place the pump on the floor, or on any level below the level of the tank, there are several precautions to be observed: Backflow seldom starts while the pump is in operation; it is when the pump is not operating that the greatest danger occurs. Backflow may be started by several actions.

(1) The tendency of water to rise in a narrow tube is known as capillary action. If the water in the tank is very close to the top, it is possible for water to rise in the air tube by capillary action to a point where it starts a downward flow and a siphoning action occurs.

(2) The cooling down of a warm pump can cause the air inside to contract and draw the water down.

(3) Over- oiling the pump can cause excess oil to enter the lines. Air pressure will keep the oil clinging to the inside walls of the vertical tubing, but with the air pressure removed; the oil starts to run back. As it collects in droplets, a vacuum is created behind it strong enough to start a siphoning action.

In order to prevent this, keep a small surgical type “C” clamp handy. When, for any reason, the pump is shut off, clamp shut the line leading to the pump. Also shut all air valves tightly. Whenever oil or moisture is seen in a tube, discard that piece of tubing. It is also a good idea to clean the pump when excess oil appears in the line.