clean tank

[guppies]

I have a few tanks, 3- 10 gals, 1 - 5 gals, 1- 25 gals and 1 - 100 gals, some of the tanks (glass) look a kind of white (cloudy not very clear and clean) should I clean it or how offen we clean the glass.
Thanks

[OrionGirl]

Haziness is usually the result of water deposits, as the water evaporates from the tank. Regular topoff will prevent it from occurring. Vinegar on a scrubby pad will remove it--but be prepared to add a little elbow grease.