My tank is 80 gallon. I have a kit to test my own water and the readings seem to come out good. That is why I tookl some water to two different places to see if they came up with anything and they also said the water was fine. The fish I was losing the most were the yellow tangs. I also lost an atlantic blue tang, some yellow jawfish and a few misc. I haven't lost any fish in a few weeks now. I've had this tank set up since Dec. I acclimate the fish using the drip method. Thanks for you help.