Goldfish with red dots

[Chris2003]

My water quality is fine - 0 ammonia/ 0 nitrite. My pearlscale’s belly and behind has a lot of these pin like red dots, he has been eating fine although it seems he is bumping to things more than usual, I’m unsure if this is flashing or is it’s just because he’s a pearlscale and being derpy. Can anybody help me diagnose this please? Thank you

[Autumnsky]

Are you using a liquid test or strip test?

What are the levels of
Ammonia,
NitrIte
Nitrate
pH

Temperature
any other numbers you measure