guppiemama

update:
I stopped changing the water and stopped adding chemicals except for Top Fin bacteria suuplement. I took 2 cups of sand from the other tank, put in a sack made from pantyhose and put it in the problem tank. Every couple of hours I'd sqeeze it repeatedly until it no longer gave off a slight cloudiness. When it seemed that the sand was clean I dumped it back into the "good" tank and refilled the pantyhose with more sand and repeated the sqeezing procedure (over a three day period, beginning last Saturday.) On Tuesday the ammonia was gone. It's still gone-tests 0 ppm. I'm a happy camper. I lost no fish, although I did take some to lfs to sell for me to reduce population as an extra precaution.