How to Calculate Aquarium Pump
How to Calculate Aquarium Pump
An aquarium pump is needed to circulate water in the aquarium. This allows the water to move through the filter and keep it clean.
The next question arises here is what should be the size of the aquarium pump. The aquarium pump is available in two sizes. Namely, air pump and water pump. The size of the aquarium pump should be chosen as per the tank’s capacity.
Air pumps are rated in flow rates as per aquarium size in gallons. If the only purpose of the aquarium pump is to push water through an under gravel filter plate, then the rating of the pump should be matched with the size of the aquarium.
If you want to add additional aquarium toys and decorations, the pump needs to have additional flow capacity. Thus, select an aquarium pump that is rated for a larger tank than the one you have, so that there is an excess volume of air available for additional uses.
The volume of the aquarium should not be more than 30 – 40 gallons, in case you are using air pumps for tank having only under gravel filter plate as the filtration medium.
Water pumps are also known as Power heads. The power heads are rated based on gallons per hour (GPH). A 150 GPH rating means, the pump can move 150 gallons of water in an hour.
Power heads circulate more water than air pumps. They prevent dead spots by bringing water up from different levels. Thus, they are more advantageous than air pumps except for the expense involved.
The amount of water movement needed also depends on the size and type of the tank. The capacity of the tank (in gallons) is multiplied with the “turnover rate” of the fish.
Tank Type Turnover Rate
Freshwater Tanks (small fish): 3 – 4 times per hour
Freshwater Tanks with Plants: 2 times per hour
Freshwater Tanks (large fish): 5 – 6 times per hour
Saltwater Tanks: 5 – 7 times per hour
Saltwater Reef : 7 – 10+ times per hour
For healthy environment in your aquarium, the water must be circulated completely at least 5 -6 times on an average in an hour. Therefore, if the capacity of your aquarium is 20 gallons, then an aquarium pump capable of pumping 20 gallons of water 5 times (20 x 5) or 100- 120 GPH is required.
Selecting an aquarium pump that circulates water 10-times the capacity of the tank is acceptable.