Hi Dana, welcome aboard! :thup:
Found this article, hope it helps...
What can you use to safely clean the glass?
Vinegar.
There are a rare few commercial window glass cleaners made out of vinegar that do not contain ammonia, but they can be difficult to find and are costly. But why not make your own? You can make an excellent window glass cleaner from ½ cup of ordinary white vinegar dissolved in ½ gallon of distilled water. You can purchase clean, brand new spray bottles in the Big Box store, and you can add your home-made window cleaner to the brand new spray bottle. Mark this bottle for aquarium cleaning purposes, and your fish will be perfectly safe.
Well, wait a minute… you don’t have to confine use of your home-made spray to the aquarium. Actually, you’ll discover that your homemade glass cleaner works very nicely on all glass surfaces, including windows and mirrors. Once you use this homemade cleaner, you probably won’t want to buy expensive commercial glass cleaners again.
Last, how about those unsightly white deposits that accumulate on the cover of the aquarium, or on the black plastic trim? Well, your homemade vinegar glass cleaner works there as well, only you don’t want to spray it directly on the aquarium surfaces above the water. Instead, spray a little on a clean cloth and use that to wipe down the top of the aquarium. It will remove those white hard water deposits on the aquarium, restoring the cover to a like-new appearance.
Even if a couple of drops of your homemade vinegar spray should enter the water column, it won’t be toxic to your fish, and it won’t upset your water balance. Natural buffers in your water will very quickly neutralize the acetic acid in the vinegar, and no harm will come from it.
Keeping your aquarium clean and sparkling is easy and safe. And now you know how to do it without investing wads of money in expensive aquarium cleaning supplies