By Steven Pro

Air pumps are not utilized as often as they once were. Back in the days before safe submersible water pumps were the norm, all hobbyists had to operate the undergravel, box, sponge, and assorted other filters for their aquariums with air pumps. That said, air pumps still serve many useful purposes today. They can be used to operate air-driven protein skimmers, which can be quite effective and efficient. They can be used for sponge filters, which are exceptional for inexpensive and effectual biological filtration for quarantine/hospital tanks, commercial fish hatcheries, or even small home breeding and rearing setups.  They can simply provide some additional aeration or movement in a display. Last but not least, they can be used to make little plastic treasure chest open and close or a small Sponge Bob Square Pants dance underwater! Whatever your desires, there is an air pump out there to meet it.

Most modern air pumps utilize an alternating electromagnet to move armature that is connected to a cup shaped diaphragm. The diaphragm pumps in and out much like a plunger. It has check valves attached which only permit air to enter one way while being pumped out another. This creates a reasonably steady stream of air. It also does this in relative quiet, since the armature’s base, as well as the diaphragm is all constructed of rubber. This isolates and minimizes vibration causing noise.  The first several pumps we will look at are diaphragm pumps.

Coralife (formerly marketed under the Tetra label) Luft Pump:

These are by far my favorite air pumps. I have used a large number of these for the past several years to run air-driven protein skimmers as well as to operate sponge filters. They are quiet, powerful, reliable, reasonably priced, and only use 5 watts! They even come with a rheostat to adjust the air output. They cover all the bases of what a good air pump should be and are the standard by which I judge all other air pumps. <Editor's note- I have had a Luft pump in almost continuous operation since I purchased it...in 1982!!- S.F.>

Penn-Plax Silent Air:

When these pumps came out about six or seven years ago and they made a very good first impression. They were very reasonably priced. In fact, they were some of the cheapest air pumps one could buy. They were also fairly powerful. The downside is they were on the noisy side. If you wanted to run a sponge filter for say a quarantine tank in a fish room, basement, or other area that was not a common living area, they would be a very good choice. But, if the pump has to be around people and quiet operation is a concern, there are better choices.

Tetra/Second Nature Whisper:

This is yet another older air pump series. I don’t believe they are still available, at least not from the original manufacturer. I have heard that someone somewhere has the old molds and is still making these pumps, but I can’t confirm this story. What I can tell you is these were my favorite air pumps of the day. They came in a wide variety of prices and sizes to fit most any need. They were reasonably quiet and reliable. They were also easy to service and replacement parts, mostly new diaphragms, air filters, and check valves, were widely available. Unfortunately, they were replaced with the so-called ‘new and improved’ Tetratec line of pumps.

Tetratec Deepwater:

These pumps were initially more powerful and quieter than their Whisper brethren. Unfortunately, their diaphragms seemed to go bad quickly, losing power. Replacement parts are harder to come by, and even if replacement diaphragms were easy to find, they would need to be replaced unacceptably often.

E. G. Danner/Supreme Dynamaster:

These old school pumps are powerful, but very noisy. Unlike the previous pumps which use diaphragm technology, the Dynamaster has a large electrical motor which spins in one direction. The motor is connected to two pistons which pump out alternating blasts of air. The whirling of the motor along with the direct mechanical links to the pistons makes for a noisy yet powerful pump. These pumps are fairly reliable and easy to service. If one was operating a small fish room in an area away from the general family living area, it is not a bad choice.

Whitewater Linear Piston Pump:

While definitely not for everyone, these pumps are impressive. The smallest model I have seen for sale pumps out 2.5 cubic feet per minute.  To get a sense of how much air these pumps move, I use one of these models to operate twelve 1” airstones at 12” deep and there is plenty of air pressure to spare. They are extremely powerful, but that output comes along with a high initial purchase price and electrical usage. They are also not the quietest units I have used. But, in all fairness, to recreate the amount of air this one unit provides would require a small army of Luft pumps. While one Luft pump is quiet, a dozen acting in unison might be something else all together.

Tips:

Whichever air pump you chose, there are a couple of things you can do to make them function at their peak. For one, don’t forget about preventative maintenance. The little air filters on these units should be examined at least monthly and replaced as necessary. By maintaining a clean air filter, the pump won’t have to work as hard to pull in fresh air and can conversely pump out more.

Also, take steps to minimize the noise. Placing the unit on a soft pad can help tremendously. Computer mouse pads work extremely well, as do small Styrofoam blocks (like the kind you can create from broken fish boxes) or squares from leftover rubber pond liner. Fish keepers are a resourceful lot generally. Reuse and recycle whatever you can.

Conclusions:

By far, I like the Luft pumps over most any other make and model. They are reliable, powerful, adjustable, quiet, and reasonably priced. For larger applications, consider a linear piston pump, or even a blower. But, for most hobbyist needs, the Luft pump will serve you well.

And, don’t discount air pumps out of hand in favor of more expensive and sophisticated alternatives. I (and other old-school aquarists) have a soft spot in my heart for air pumps. They is nothing more relaxing to me than seeing a well designed fish room and hearing nothing more than the soft, gentle sounds of bubbles in water. Definitely, don’t knock them until you have tried them.