I have since worked out that he has been tail biting. Huge chunks of tail have disappeared, and I've caught him spinning and chasing his tail. It's telling me I need to move him soon, so I'm going regular water changes and helping to get his wounds healed. Fingers crossed!

Hi Fishlady,

Thank you for your reply!

I have treated him again for fin rot.

He is in a 20 litre tank (to be moved to a larger tank soon, but I want to make sure he is healthy first.)
Ammonia: 0
Nitrite: 0
Nitrate: 15
Ph: 7.8
Soft water

I suspect the current in his tank is too strong, hence why I'm moving him to a tank which has a filter that can be adjusted. And I think he has had problems with getting stuck near the filter inlet, so I blocked access so water can flow in but he can't. Im just so confused how over the course of a day he can go from a full tail to it being shredded. It's breaking my heart! I literally set up the larger tank a month ago and was planning to move him this week to get him out of there, then this happens. Here's to a rapid healing so I can move him!

Are my files visible?

Hello

If any of you can help, I would be so grateful.

So, my fighter has this problem which I hope you can see in the photo.

This is not the first time this has happened. 2 months ago, when I came back from holiday, I saw that his tail has been damaged and the tank had some fungal growth. I treated the tank and him for fin rot. Since then, his tail grew back splendidly. The membranes had recovered and he was happy and healthy.

On on Friday I went away and came back on Sunday. Gone for only a day, his tail has been torn to shreds again. I thought I had prevented it. I put gravel around the base of the filter, in case he had got stuck before and removed anything sharp. I did a water change the day before I left and have done another one the day I got back to clean the he water.

Please, any advice would be appreciated.