Aquarium Pumps - starting with the basics

An aquarium is like a mini-environment for the critter you choose to keep. The correct balance of temperature, aeration and filtration is essential for the health of your water bound pets.

Bigger is not always the better when it comes to aquarium pumps. Due to the amount of heat that large pumps can generate, water temperature can raise and could destroy the environment required by the fish and other animal life in the tank. If the pump capacity is too small, it will be insufficient to maintain the environment required for a delicately balanced ecosystem.

If the aquarium is a closed, freshwater system, the filtration needs a fairly powerful pump with a high flow rate. Open systems, on the other hand, need lower flow rate pumps such as those required by wet and dry filtration systems. The static systems use canister or module filters that have a greater resistance that requires a greater water pressure.

Once upon a time, separate air pumps were necessary to ensure adequate oxygenation, or a large number of plants, to help clean out the carbon dioxide, and add oxygen. Today, however, modern water pumps have reduced the necessity of dual aquarium pumps by using the water movement generated at surface level to provide sufficient aeration. Many aquarium enthusiasts us what is called a protein skimmer. This unit pumps minuscule air bubbles in to the water that collect the protein waste. If you go the route of a protein skimmer, it should be powered with a separate pump since it can otherwise be difficult to keep the skimmer and your water pump requirements properly optimized.

Neither the intake nor the return of an aquarium pump should be restricted to adjust flow. Doing so could either overheat the pump or reduce its effective life. It is also very important that the return line be made of a flexible tubing. If it must be hard plumbed, then it should be plumbed with wide angular sweeps rather than ninety degree bends. This helps the pump to run at the correct temperature, whereas severe direction changes increase pressure in the pump and force it to operate at a higher temperature which will shorten the life of the unit.

In order to choose the correct system for your freshwater aquarium you will first need to know how many water changes per hour you need. This number can vary for the type of aquarium you have. For a fresh water tank, you will need to change 2 to 3 times an hour, and for a salt water version, 3 to 4 times an hour. A reef aquarium is specialized and has the much higher requirement of around ten times. You can then calculate the capacity of pump you require from the volume of your tank. Don’t use the maximum capacity of the pump though. Go for about 75%, so a 400 gallon an hour pump at 4 changes an hour would be suitable for a tank of 300/4 = 75 gallons.

The head pressure of the pump is also important - this is affected by the number of 90 degree bends in the water delivery system. The head pressure is the distance from the inlet of the pump to the discharge, with an extra one foot added for each 90 degree bend, and a foot of pressure for every 10 feet of horizontal pipe. So if the distance from inlet to discharge were six feet, with two 90 degree bends and six feet of horizontal pipe, the head pressure would be 6 + 2 + 0.6 = 8.6 feet. This is important because it gives you a solid number to compare against the pump specification.

Knowing this simple aquarium calculations ensures that you can confidently pick out the correct pump for purchase. No waisted money - the aquarium pump you purchase will fit the bill. The important figures are the pump rate and the maximum head pressure - given the simple calculation above, you can design a new system precisely according to your needs.

Your aquarium pump should be checked and maintained regularly. Every three months or so, you should clean the impellers and it's  chamber - cleaning out the algae or any other debris that can reduce its service life. If you maintain your pump regularly and follow the above advice it should provide you with trouble free service for many years.

Common misspellings: quarium aquraium punp pupm