My fish's belly is floating and my fish turned white, how did this happen? (P.S.) my fish is really fat...?

I just got a new filter for my 10 gallon fish tank because the last one my fish kept getting stuck behind it and they couldn’t get out. Even so that problem is fixed I got the to...

So far, I’ve only seen 6 fri (2 died because they were too weak). Isn’t a guppy supposed to have 20-60 fri? Is there something wrong with her or do I need to give her more time...