@Cory
I've only ever tested the ammonia of my tap water which was 0. The last water change was done about 3 days ago. I haven't done any de worming (is that the same as internal parasites?).
The mbu did have whitespot which I treated 3 times within 3 days and he's been healed for 4 days now. He was eating when he had whitespot so I don't think it's because of that, just thought I'd mention it.