How to use Airline Accessories in Your Aquarium

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How to Use Airline Accessories in Your Aquarium

Aquarium air pumps are very easy to use. Just connect the pump with the device using airline tubing. So why is there so many accessories for airlines? And which ones are you really going to use? We’ll be briefly explaining five commonly used parts of an airline to transform how you use your air pumps.


1. Check Valve

If you only get one item from this list, a check valve is an essential must-have. This valve contains a flapper, or stopper. It allows air to flow in one direction (into your tank) and prevents water from flowing in another direction (outside the tank). This important accessory, which is very inexpensive, prevents water escaping from your aquarium when the pump goes out of power. Water leakage out of the airline tubing usually results in damage to your air pump, as well as flooding all over your floor. If appliances or power strips are in contact with the water, it can cause an electrical fire.

Every aquarium device that uses airline tube is required to have a check valve. This includes aquarium ornaments, sponge filters, brine shrimp hatchery and carbon dioxide (CO2) injection systems. The only exception to this rule is when the CO2 tank/air pump is located above the aquarium’s edge. For installation, simply cut the airline tubing between the device and air pump and connect the check valve in between. The flapper, which looks like a horizontal or colored bar at the end of the check-valve with the flapper should face the air pump. You can’t turn the air pump on if the check valve is installed backwards.

Connect the check valve to the air pump. Make sure the horizontal or colored bar faces the air pump.

The best practice is to place the check valve outside the aquarium (not in the water), close to the top of the fish tank. This position stops the water at the rim rather than near the air pump where the water pressure in the airline tubing could cause a leak. Make sure that the airline tubing has not been twisted or damaged. Finally, check the airline tubing to make sure it hasn’t dried and hardened over time, which could cause the connection to loosen and drip during a power outage.

2. Air Valve

The air valve looks similar to a “check valve”, but it controls the flow of air from your aquarium to the pump. You may find an adjustable knob on some air pumps that allows you to adjust the pressure. However, if you don’t have one or the bubbles are too strong then this tool is for you.

To install an air valve, cut the airline tubing between the air pump and the air-driven device. Next, connect the cut ends of airline tubing to each air valve end. It doesn’t matter which direction. Turn the knob until the flow is reduced. To increase flow, loosen it. A small amount of air can still escape through the valve even if the knob is fully tightened. This prevents back pressure buildup and can potentially cause damage to your air pump.

An Air Valve controls the amount air flow from your air pump to your air-driven aquarium device.

As with the check valve, we recommend that you add the air valve near the rim of your fish tank for easy access. Also, make sure you make clean cuts in the airline tubing and check the connections periodically to make sure the air valve is still snuggly connected.

3. T Splitter

The T shape of the tee splitter splits air into two streams. This functionality is useful if you only have one air pump but wish to run a second air stone or aquarium decoration in the fish tank. A second use for this functionality would be to divert the air from your main aquarium to another tank or a quarantine bathtub. Each pack comes with five T airline connectors, so you could theoretically chain multiple splitters together to create additional air streams.

The air flow from the green air pump is divided by the T splitter, and the air valve regulates how much air gets to the sponge filter.

We highly recommend using air valves when splitting the air stream so that you can fine-tune how much air goes to each line. As usual, ensure that you use airline tubing with clean-cut ends and periodically inspect the connections to make sure they haven’t weakened over time.

4. Gang Valve

A gang valve is an efficient accessory to split one air stream into multiple routes. The model we offer features four outlets and up to two inlets. The two inlets allow you to add one or two air pumps as desired and then split it up four ways. You can also connect two daisy-chain gang valves together to give you eight ways of splitting your air.

A gang valve is a great way to split air between multiple aquariums or air-driven devices.

Keep in mind that every split of air results in a weaker output, which means less air passing through each outlet. The more outlets you have, the more adjustments need to be made on each air stream. There’s no need for additional air valves as each outlet has its own adjustable switch that regulates how much air is allowed to each device.

5. Air Stone

An airstone is a small weighted bubbler that makes very small bubbles in water. This simple accessory helps to gradually diffuse air into the tank, improve oxygenation of water, and minimize the amount of bubbling noise you’ll hear. You can use an air stone by itself or in conjunction with a sponge filter to improve the efficiency of the filtration. The air stone produces a steady stream (instead large, intermittent bubbles), that lifts the sponge filter like an escalator.

This diagram shows where an air stone goes inside a sponge filter to optimize its performance. To install an air stone inside a sponge filter, read our sponge filter installation guide.

Running an air-driven device like an aquarium filter, air stone, or bubbler is one of the easiest ways to increase surface agitation and oxygenation in your fish tank. For more details on how to set up a fish tank air pump (and make it quieter), read our full installation guide here.