DO NOT USE WINDEX. My 45 gal. would not cycle - ammonia was off the charts (in the unreadable range) after 4 weeks of waiting (fishless cycle) and 20 visits to the local fish store to test the water.
THEN, my bf casually mentioned that "I can't believe the ammonia is this high - I washed the tank inside and out with Windex"
Of course he had no idea. He bought it used on CL as a surprise gift and "washed" it out with all the gravel left in there too. So I had to break down the whole thing, clean it all out including the gravel with vinegar and boiling hot water and rinsed it like 100 times before I was ready to try the cycle again.
I def. learned the hard way even tho. I had nothing to do with it initially LOL.