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Can Fish Live (Or Breathe) In Coffee?

Can fish actually live in coffee? It’s a shower thought that has been on my mind since the last time I showered. You’d think not, but are there any reasons why that is, and is it that harmful? Keep on reading to find out.

Let’s get started.

Can Fish Live (or Breathe) In Coffee?

Fish can’t live in coffee, besides caffeine, coffee is acidic and lacks oxygen. So technically with the correct oxygen concentration, it could be possible, but if it’s pure coffee then it’s just impossible as the body can’t filter out these things. Fish heavily rely on their environment to not be too salty or not salty enough, as well as not too acidic or alkaline.

Fish also experience stress such as osmotic stress, ph stress, viscosity stress, turbidity stress, chemical and other mineral stress, heavy metal stress, etc. So, putting a fish in coffee for more than a few seconds would likely put a strain on its gills.

Think about it this way, if you were put in a world that had oxygen, but was also filled with particles and ash, you wouldn’t survive either. You need the right amount of oxygen in order to survive, of course, your lungs can filter out a lot but it will take its toll on you sooner or later.

If you like to go fishing then you might want to use coffee grounds as bait.

What If You Spill Coffee In Your Fish Tank?

Now that you know coffee is not suitable for fish, what if you spill some of it in your fish tank by accident? It depends, if you spill some coffee in your 70-gallon tank then it most likely won’t hurt your fish. It might even make it more favorable for some species. But if you have a 10-gallon tank and spill some coffee into it then you may not only have a problem but also stressed fish. It may not kill them but a light partial water change is recommended. You can also toss a small bag of aquarium charcoal in your filter for a few hours to clean up the water.

The Bottom Line

Fish can’t live in coffee. Even without caffeine, coffee is still more acidic than pure water and it lacks oxygen. This will stress the fish and if you put it into coffee for just a few seconds then it will put a strain on its gills.

Now if you spill a bit of coffee in your fish tank then it’s not the end of the world, but you should take action immediately if you have a small fish tank. A light partial water change is recommended, you can also toss a small bag of aquarium charcoal in your filter for a few hours to clean up the water.


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