Can anyone Help!

[Elizabeth2021]

Hi everyone, Can anyone tell me what this is on my black moor. We got 2 of them in March when they were small but they have grown a bit since then but now this has appeared on one of them and the other one only has one small patch/dot not sure how to describe it. I’m really worried that it’s something bad but I’m new to this so have no idea. Please be kind thank you.

 

[Gemjuice1989]

Why are some of my platty fish turning grey? And why are some looking like they have a hump? The tank is clea