I hav 75g oscar tank. I have a albino pleco too in it. I change 50% water weekly.I hav a glass wiper which I use for the front glass of the tank. Bt the sides and the glass on back sides needs some wash.my single juvi pleco alone can't handle all the algae.thinking of adding some snails in it.wat types of snails r best for this purpose.how many number of them I can add? Plz advice.all the suggessions,advices r most welcome.thanx