Can Platy Fish Live Without Oxygen?

Fish require oxygen to survive, just like any other living creature. But is the oxygen in water enough to keep platy fish alive? Or do they require an additional source of oxygen?

Platy fish cannot live without oxygen, and the oxygen that’s naturally present in water is not enough to meet their requirements.


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Therefore, oxygen-promoting devices are required to supplement the levels of oxygen in the tank.

In this article, I’m going to talk about oxygen exchange in water, whether platy fish require a water pump or air stone, and what you can do to drive more oxygen into the water.

Oxygen Exchange in Water – How it Works?

Platy fish breathe by pumping water through their gills, thus getting to oxygen dissolved in their water.

However, water is made up of two parts hydrogen and one part oxygen (H2O), which isn’t enough for fish. They require oxygen molecules (O2), which they can get if oxygen is dissolved into the water.

Oxygen gets into the water from the atmosphere through surface agitation or by adding fresh water into the aquarium, which contains dissolved oxygen.

The surface of the water can be agitated with the help of an air pump or an air stone.

Do Platy Fish Require a Water Pump or Air Stone?

Oxygen reserves in water can easily get depleted and many factors can contribute to this including overstocking the aquarium, overfeeding your fish, which results in an increased waste production, and not keeping up with regular water changes.

When oxygen levels drop and toxin level rise, fish are exposed to all sorts of diseases. You’ll often see some fish coming to the surface of the water gasping for air.

Because platies enjoy well-oxygenated water, it’s a good idea to invest in some surface agitating device for your aquarium.

For small aquariums, an air stone will do the trick, while larger aquariums may better benefit from a water pump to promote oxygen exchange in water.

The bubbles created by an air stone or water pump will rise to the top of the aquarium, breaking the surface and agitating the water, so more oxygen can get in.

If you’re going with a water pump, make sure it’s not noisy as too much noise can be stressful for your fish.

How to Drive More Oxygen into the Water?

Besides having an air stone or a water pump installed in the aquarium, there are other ways to promote oxygen production in the aquarium.

For more natural – and less noisy – alternative, you can populate your aquarium with live plants that will create a self-sustaining ecosystem to promote more oxygen in the aquarium.

Plants will feed on the CO2 and nitrates released by your fish, offering oxygen in exchange. If there are enough plants in the aquarium and you have only a few platy fish, you may be able to circumvent the need for other types of surface agitators.

Plants like crypt wendiis, waterweed, hornwort, moneywort, and others are great for platies and promote oxygen in water.

Remember that certain plants require a lighting system, so if you don’t want to invest one, I recommend that you choose low-light aquarium plants, which will do fine only with natural light.

Some low-maintenance and low-light aquarium plants include the anubias nana, java moss, micro crypts, hornwort, crypt wendtii, and many others.

High-maintenance plants require trimming, artificial lighting, fertilizers and appropriate substrates to sustain plant growth and development.

Apart from having some sort of surface agitator in the aquarium and/or keeping live plants, there are other things you can do to minimize the loss of oxygen in the aquarium like making sure your aquarium is not overstocked or performing regular water changes.

Is a Filter Needed for Platy Fish?

As fish produce waste, food particles decay, and the leaves of plants decay, they all release toxins like ammonia, which builds up in the aquarium over time.

Besides regular water changes and removing uneaten food and dead plant leaves, you should also consider setting up a filter in your aquarium, which will aid in keeping water parameters at optimal levels.

It’s important to make a distinction between surface agitators and an aquarium filter system, which helps clarify the water and reduce toxin levels.

Surface agitating devices like air stones and water pumps don’t help in eliminating toxic waste products from your aquarium. Filters, on the other hand, are designed to help reduce waste and debris in your aquarium.

There are various filters for aquariums including sponge filters, hang-on-back filters and canister filters. The latter ones are a better choice for larger aquariums, the former ones are for smaller aquariums.

Filters are a requirement with certain fish that are known to have a high bioload such as mollies and guppies. But is a filter required for a platy fish tank?

Platy fish don’t have a particularly high bioload, but filtration is beneficial for them too. For some platy variations like the Swordtail platy a filter is a requirement since these fish are more sensitive to toxins in their water.

The filter media in aquarium filters gets populated with beneficial bacteria, which aid in transforming harmful toxins like ammonia and nitrites into less harmful ones like nitrates.

Therefore, a filter system is definitely an equipment you should invest in if you’re setting up a platy fish tank, however, having a filter in the aquarium does not absolve you from doing other maintenance tasks that are required.

Even if you have a filter, you still need to perform regular water changes and routinely clean the aquarium substrate and other surfaces in the aquarium.


In conclusion, platy fish cannot live without oxygen and a surface agitator device – be it an air pump, air stone, or filter system – is required to promote oxygen exchange in the water.

Besides an air stone or pump, make sure you also invest in a filtration system if you want optimal water parameters and thriving platies.

I hope my article has provided you with the necessary knowledge to make sure water in your platy fish tank is well-oxygenated and clean.

Questions and Answers

New to platys. Purchased 2. 5.5 gallon tank for now. Will purchase a 10 gallon in a few months. I have a heater also. Any tips. Need a few plants

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