My Cloud Minnow Is Sick

I can’t figure out what’s wrong with my Cloud Minnow. It started swimming funny a few days ago. Then it started lying on the bottom of the tank. It’s eating fine. It still swims around fine now, when it does swim. But, it’s sitting on the bottom mostly. It looks like it has internal organ bleeding on both sides. The red spots on it’s sides are symmetrical. There’s a bump on one side. I think the red spots might be lesions. I can’t figure out what’s wrong with it? I posted s

 

Try adding some melifix

 

Try adding some melifix

Thank you!

 

Can you post a picture of your tank? If not, do you have any sharp ornaments is could have cut itself on? What are your water parameters? Do you dechlorinate the water? Do you have a filter? Do you have a bubbler? How big is the tank?

 

It’s a 20 gallon tank. I don’t de chlorine the water but I do have a filter. I’ve had the fish for over a year now. I have it quarantined but the only thing I think of that might be sharp in the tank is a couple lava rocks. I clean the tank regularly but I don’t have a test kit for water parameters. I’ve been using the Melafix it seems to be helping a little. The pet store said to use tetracycline I haven’t started using that one yet. I don’t have a bubbler.