Losing scales and red skin?

[Cryptaed]

Hey all. My betta fish is a platinum (but he had grown red in his fins (not ammonia poisoning)) but he is losing scales and getting red spots, and he also has gold splotches near his gills on both sides. I can't figure out what's wrong but he is super lethargic, staying at the very top of the water and not moving much except to eat, which he is eating fine.

I also have some snails in the tank and they are all at the top of the water like too.
Ammonia is 0, nitrite is 0, and nitrate is 5. Ph is 8.0. Temp is 80. I do weekly water changes including cleaning gravel and I replace maybe 30%.

It's almost like the tank has not enough oxygen, but it is reading fine.

Anyone have any thoughts..? I have no clue what to do.

 

[Autumnsky]

Are you using test strips for testing or liquid test kit?

Any time snails go to the top it is indicative of a problem. It normally means there is an unsafe parameter. Or the O2 is low.

Any time this happens I usually will do a 30% water change. Also if you use Prime or other water conditioner which detoxifies ammonia, nitrite and nitrate you can add a healthy dose and see if the snails automatically begin to move lower in the tank, in about an hour they are usually gone off of the sides. If they do it means something in the tank was in an unsafe number. Test kit or not.

 

[Blueberries]

This sounds like Velvet - I have no experience in this but came across it reading about worms and parasites. Wishing you and your fish the best of luck!https://www.bettacarefishguide.com/velvet-in-bettas-everything-you-need-to-know/#Recap

https://www.bettacarefishguide.com/...-symptoms-treatment/#What_Causes_Anchor_Worms
This is the site I was reading when I came across Velvet. I would go over all of these velvet, ich, columnaris and gill flukes.

 

[Blueberries]

Any updates?