Hey let's see a picture. What kind of lighting are you running? To me you need a larger clean up crew. How long has the tank been up? Are you getting any algae on the glass, rock, substrate? 5 snails in a 220 is way under powered to me.
as a reference i have 30 hermits, 30 snails, 5 emeralds, a sally lightfoot and coral banded shrimp in my 55g, i may have over done it just a bit but i expect my baby humma humma to slowly pik them off
I have a bit over half of what dangalla has in 55g + 2 Skunk shrimps. They did clean up my tank in 2 days after we had changed the lighting and algea was really starting to show up quickly.