Just as humans need air to breathe, fish need water circulation and aeration. And a pump is essential to ensure your fish get the oxygen and nutrients they need.
What are the different types of fish tank pumps?
There are two main types of fish tank pumps:
- Air pumps, which oxygenate water to keep fish and plants alive. An air pump adds air to the fish tank through airline tubing in the form of bubbles. The pump sits outside of the fish tank, above the water surface.
- Water pumps, which increase water movement in a fish tank or move water from one place to another, like from a sump to a fish tank. These pumps aerate fish tanks by producing a current that allows air to enter the water.
Fish tank water pumps
What is a fish tank water pump and how does it work?
A fish tank water pump aerates and circulates water to keep fish healthy.
The pump creates a current that feeds the water in the fish tank through the filter. The constant flow of the current distributes nutrients evenly throughout the fish tank, which helps prevent disease in fish.
In the middle of a water pump, an electric motor spins an impeller (one or two plates surrounding a series of vanes), producing kinetic energy.
An intake port sucks water in, and the kinetic energy from the impeller transfers to the water. The energy forces the water into the fish tank, and the water circulates into the filter, making its way back into the pump.
The current keeps all the water in motion, preventing stagnant water.
Do you need a fish tank water pump?
Small tanks don’t typically need water pumps, which are usually more beneficial to larger aquariums. So, if you have a small fish tank, an aquarium filter is likely all you need. If you have a larger fish tank, buying a water pump is a good idea.
If you’re not sure whether you need a water pump, keep an eye out for algae growth or sluggish fish. These are signs of low circulation, in which case a water pump may be your solution.
How should you clean your water pump?
To clean your water pump:
- Turn off the water pump and unplug the power source.
- If you have an external pump, remove the inlet and outlet tubing.
- If your pump is in a sump, remove it from the sump and controller.
- Remove the main housing from the water pump. You may be able to twist this off, but some pumps contain screws.
- Remove the impeller and clean this and the pump housing with fresh water.
- If there is calcium on the pump, mix one part muriatic acid with three parts citric acid. Soak the pump in this solution and rinse.
- Dry the pump.
- Reassemble the pump.
- Reconnect the power (and tubing if necessary).
Bonus Tip
You should clean your water pump at least every four to six months. Some pumps require more frequent maintenance, so make sure you check the manual.
If you have a reef tank, you’ll need to clean your pump every two to three months.
Fish tank air pumps
What is a fish tank air pump and how does it work?
A fish tank air pump injects air into the water in your fish tank.
The pump forces oxygen into the water, and carbon dioxide releases into the water (with the help of surface agitation). The pump causes this surface agitation by displacing the water with air bubbles.
Do you need a fish tank air pump?
Small fish tanks don’t usually need an air pump. But the more fish in your aquarium, the higher the chemical imbalance in the water may be, making an air pump a good idea.
Similarly, cold-water tanks don’t typically need an air pump. But oxygen levels in warm water can decrease, so fish that live in warm water can benefit from an increased oxygen flow.
If you have live plants in your fish tank, buying an air pump could also be a good idea. Plants absorb CO2 and release oxygen during the day. But this process reverses at night, which can see plants diminish the oxygen levels in the water while raising CO2 levels. In this situation, an air pump can keep oxygen levels up.
If in doubt, buy an air pump if your fish don’t seem to be getting enough oxygen and show the following symptoms:
- Resting more than usual.
- Swimming to the top of the tank for oxygen (although this could mean the water contains too much ammonia – test your water to check).
- Moving their gills quickly.
An air pump can also agitate some kinds of fish, like bettas, so check before you invest.
Do you need an airstone with an air pump?
When you buy an air pump, you’ll also need an airstone. These stones, made of porous stones or limewood, reduce the size of the large bubbles that the air pump produces to make them a friendlier size for fish.
An airstone:
- Increases water circulation.
- Increases surface agitation, forcing more oxygen into the tank.
- Reduces noise.
- Reduces the size of bubbles that come from the air pump.
In short, an airstone improves oxygen levels and reduces stress for fish.
What is a good flow rate for your fish tank pump?
Your pump’s flow rate should be at least three times higher than your fish tank volume. So, if your fish tank holds 180 litres, like the Juwel Rio 180 (which comes with a water pump), you’ll need a water pump that has a flow rate of at least 540 litres per hour.
You’ll also need to accommodate any obstacles in your fish tank that can slow down your flow rate. Consider the height of the pump head, indirect plumbing routes, and the size of the inlet/outlet tubing.
To be on the safe side, you could buy a water pump with a flow rate that is higher than three times your fish tank’s volume.
That said, be careful not to buy a water pump with a flow rate that is too high for your fish tank. An overly high flow rate can cause too much circulation, which can harm fish or force water out of the aquarium.
Lots of pumps have adjustable flow rates and timers so you can set your flow rate in line with your tank size.
Does your fish tank pump need to run constantly?
Whether you have a water or air pump, this should run all the time in your fish tank. The pump offers life support for fish and plants, so leave it turned on.
About Warehouse Aquatics
The Warehouse Aquatics mission is to offer the most choice at the best prices when it comes to your fishes’ wellbeing. We use the products on our website ourselves and are well-versed in all things fish, so we can give you all the advice you need. We’re not just here to sell aquatic supplies. We’re also here to guide you through your journey as a fish owner and enthusiast.
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