Your Resource for All Things Aquaponics

Do Fish Need Oxygen?

Do Fish Need Oxygen?

Yes! It seems strange to think that fish need oxygen, but they do!

Using their gills, fish filter oxygen out of the water. Oxygen in the water is already dissolved, making it easy for the fish to utilize it.  Fish need to live in water that has 5 parts per million and can survive as low as 2 parts per million.  Lower than that and they will eventually suffocate and die.

Our system recently ran into this problem.  After being very busy for a week, our pump became clogged with some hair algae.  This is typically something we are quite on top of, but we let it slip.  The pump couldn’t function as well and eventually the stream of water going into the fish tank had slowed to a trickle.  In our tank, the water falling into the tank is what helps in keeping it oxygenated.

When fish can’t get enough oxygen they will come to the surface and “gulp”.  This video that I took shows what that looks like when the fish start gulping at the surface.  Shortly after we got the pump unclogged and running smoothly again, the fish dove back down and were no longer struggling for oxygen.

Other things you can do to keep your fish happy and full of oxygen is to have air stones in your tank.  As with most products, the size of your tank will influence the size of pump you purchase.  The only thing you need to know is the size of your tank to purchase one though! An IBC tank, 300 gallons each, would use an airstone similar to this one.  A small, indoor aquarium would probably use something like this air pump.

Don’t forget that moving water creates the same dissolved oxygen as the air pumps would. Some systems won’t ever need to have air pumps if they have few enough fish or if the water is pouring enough to add that oxygen in the first place.  If you want to try to give your fish more oxygen without adding more money to your system, try adjusting your plumbing so the water pours into the tank from a higher spot or maybe branches off to create two streams of water rather than just one.

Take a look at the video to get a good idea what to look for when your fish need oxygen.  A full transcript is at the bottom!


So last week we had a bit of family stuff going and we weren’t able to get out to take care of our Aquaponics system really as much. Now in the back corner you can see the fish are coming up to the surface to gulp oxygen.  That is dangerous for the fish.  That, not having enough oxygen in the water. The problem that we ran into, right here on the side you can see the water that is flowing down into the tank.  The pump got clogged and the water stopped flowing into the tank as well.  The water has to be aerated going into the tank, and having that water fall is one of the huge things that helps aerate the water.  With the fish not having enough oxygen in the water they end up having to come to the surface to get the oxygen and with that happening for too long they can actually die. I’m not going to show you but we actually have two floaters in this tank that died, I’m assuming because they didn’t have enough oxygen in the water.  Which is kind of a sad thing, these are our first two that have been lost in this cycle.  But I wanted to show you what that looks like to have the fish come to the surface of your tank. You can see some all the way in the back corner now. That’s something you have to be looking for in order to keep your fish healthy and obviously your plants healthy as well.

So in order to fix this problem we got the water running again, obviously.  But the next thing we are going to do is pull out some air stones.  When the fish were really tiny I didn’t worry about having the air stones in the tank but now they are getting pretty big, they are about hand size. They are getting big enough now that it’s important now to have those air stones.  We are going to go ahead and hook those up and put them in the water and the air stones will help continue to aerate it even if the pump does get clogged up and stop pumping water to the tank.

No Comments Yet

Leave a Reply

Your email address will not be published. Required fields are marked *