Oh crap, this has me thinking... I bought my 46 front bow off craigslist, from a 28ish year old dude who was keeping a pond koi in it. It is sparkling clean, he says he cleaned it. If he in fact used windex or an amonia base glass cleaner, am i screwed?
*edit i'm guessing if he kept a pond koi in there he didn't know how to clean it properly.
honestly, i just used dawn to clean my tank that had been sitting dormant for like 10 years. I used a regular scotch brand sponge an used the softside and rough side, i have glass, so scratching isnt too big of a deal. I rinsed it a whole bunch of times to make sure that all of the chemicals were gone and voila, fish tank cleaned, fish is happy, woot woot.