Wierd Cuts and Fin Damage

[richardhmc]

My SunCatfish has developed three cuts on the side and a red anal fin. I think the red anal fin could be infection but the cuts I can't explain.

There is nothing in the tank that would be able to cut it since its a 50g barebottom tank with just a heater and AC filter.

Any ideas of what this could be and how I could treat it?

I just bought a RO/DI recently - would using RO/DI water have any affect by any chance?

I have been doing 70 percent water changes for the past few days everyday.

 

[aquaculture]

Would these be sores?

I know old thread but I would like to know more info on the topic.