Bumps on platy tail

My Mickey platy has several small raised bumps, bubble like appearance on his tail area. Near his Mickey sign. He is acting a little shy, preferring to stay alone.

Water quality is a work in progress. Long story short- ph isn't stable because gh/kh are way off. Recommended baking soda to raise ph. Finally, got ph to 7.4-7.6. Added 1/4 tsp every couple hours. Also added seashells to help with gh/kh. Added prime when I changed the water.

Ich came up when searching, but it doesn't look like it IMO. It doesn't have a salt-like appearance.

 

Can you post photos? If you don't know how here's how-

 

He's moving too much to take a pic
Tried...he sees me come up to the glass w/ the camera and he swims into hiding.

 

Ok, hopefully someone can come on and help out, my guess is perhaps fish lice, but wait until someone else can help. As its only guess. Are you sure it's a male?

 

Maybe you could try feeding him a little bit so he holds still?

 

Ok, hopefully someone can come on and help out, my guess is perhaps fish lice, but wait until someone else can help. As its only guess. Are you sure it's a male?

Without seeing a pic I have agree with you.

 

Here's the best I can get. Red area of tail fin behind Mickey spot. One little spot. Only in that area. On a human, id say it looks like a heat rash or blister.

Eta- the other side of his tail fin has a couple.

Fish lice you can see to the naked eye & move around right? At least that's what Google said. No other fish have this, and no "new" fish. We got some glo danios a few weeks ago, but nothing unusual. Can they just "show up" one day? Google made it sound like it has to carried into the tank from an existing fish.