So I bought algae wafers and I gave the snail one last night. Its been more than 12 hours and it still mostly there. Should I just leave it for him to finish off in time or remove it? And how often should I feed him?
Depending on how big your snail is, it's very likely that he won't consume the whole algae wafer. You will probably want to break them up.
For betta tanks, I use frozen lettuce because algae wafers usually pollute the tank long before one tiny snail can finish the whole thing. Furthermore, most bettas go crazy for algae wafers (most of the time their main ingredient is actually fish meal) which is no good because they just bloat the poor guys up like a balloon!