3 year old clownfish started fighting

[mochimochi]

I have had two clownfish for about three years in a 20g (they are currently the only creatures in the tank besides 1 hermit crab). In the beginning, one of the clownfish was bigger than the other (her name is nana) and was dominant over the other (his name is popo). In the last few months, popo has suddenly had a growth spurt and is now about the same size as nana and has started chasing her around and nipping her fins. nana now mostly stays in the corners of the tank but they are both still eating. There have been no changes in the tank for the last few months since my cleaner shrimp died and the water parameters are normal.

Has this ever happened to anyone? Should I return popo?

Attached picture of nana and her damaged fins on the left with popo making sure she(?) stays in the corner on the right (sorry for all the algae )

 

[Peace River]

Clownfish are wired for dominance and aggression is often a part of that process. If you are looking for a peaceful tank then this might not be the best pair (keeping two clownfish may not even be the best choice for the tank). If you are looking for a breeding pair then you may consider keeping the more dominant fish and adding a smaller replacement for the other fish once it is rehomed. Good luck with whatever direction you choose!

 

[ClownSchool]

I have had two clownfish for about three years in a 20g (they are currently the only creatures in the tank besides 1 hermit crab). In the beginning, one of the clownfish was bigger than the other (her name is nana) and was dominant over the other (his name is popo). In the last few months, popo has suddenly had a growth spurt and is now about the same size as nana and has started chasing her around and nipping her fins. nana now mostly stays in the corners of the tank but they are both still eating. There have been no changes in the tank for the last few months since my cleaner shrimp died and the water parameters are normal.

Has this ever happened to anyone? Should I return popo?

Attached picture of nana and her damaged fins on the left with popo making sure she(?) stays in the corner on the right (sorry for all the algae )

All I had to do was read the first line…
A clown needs about 30 gallons. Multiple clowns need more. I had to move up to a 55 gallon before my Clarkiis stopping acting aggressive and start acting like a mated pair again.

 

[Peace River]

While I fully agree that the tension between the fish may be lessened with more space, the statement that a clownfish needs a 30 gallon tank doesn't align with my experience of keeping and breeding clownfish. Additionally, I have visited several clownfish breeders and they typically don't keep their breeding pairs in 30s or 55s. A 10 or 20g tank for breeding pairs is common from what I have seen as well as what Wilkerson and others suggest.

 

[ClownSchool]

While I fully agree that the tension between the fish may be lessened with more space, the statement that a clownfish needs a 30 gallon tank doesn't align with my experience of keeping and breeding clownfish. Additionally, I have visited several clownfish breeders and they typically don't keep their breeding pairs in 30s or 55s. A 10 or 20g tank for breeding pairs is common from what I have seen as well as what Wilkerson and others suggest.

I don’t know about all clowns, but Clarkiis get pretty big, pretty quick, and the sites I visited all said 30 gallon minimum recommended.

What’s The Ideal Clownfish Tank Size? 5, 10 Or 20 Gallons?

What’s the ideal clownfish tank size? There is a huge signboard on the front with a photo of a clownfish in a 1-gallon deco kit and “Take Nemo home for only $80” written in big letters.

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