What I do is go into a room wayyyyyyyyyy far away from the tank, squirt some glass cleaner onto a paper towel and then wipe down the glass with it. This prevents any chemicals from actually getting into the tank. Hope this helped.
My tanks (so far
5.5 gallon Planted Dwarf Puffer tank (2 Dwarf Puffers and a lot of RCS!)
16 Gallon Planted
(GBR pair, 3 amano shrimp and a whole bunch of snails!)