Hi everyone! My name is Katie I have a semi-planted 10g with a platinum male betta (Oliver), a juli cory cat (Penelope), a black mystery snail (Leonard), 2 otto's (Dharma & Greg), an ivory mystery snail (Tiffany), and a few ghost shrimp. I'm still very new to this, I've only had my tank for about 5-ish months. I currently have some nasty algae in my tank, and my black mystery snail (Leonard) is not doing so well. He hasn't really moved in a little over a week. And I've found there's these clumps of like white fuzzy stuff that is stuck inside his shell. He sits partially open and when I touch him he closes. But I have to physically remove the white fuz every other day. Idk what it is. I took a video of me removing it. If anyone has any tips or can give me any advice, I would really appreciate it thanks guys!