I use glass cleaner, generic brand kind .... I just don't go overboard with spraying it on firehose style... just a quick mist here and there is enough to clean all the glass.
some avoid glass cleaner alltogether claiming it puts toxins in the tank ... I've never had any problems with using glass cleaner, and this warm water business does not remove greasy finger-prints or hard-water stains... is just smears things around and leaves a nice hazy film!
now if you're talking acrylic and not glass, I would not recommend glass cleaner, as it contains microabresives to clean hard glass, but will scratch soft plastic, leaving it with a permanent haze.
hope this helps