Any one know about tank water treatment?

While all fish would require you use to use a good water treatment such as Prime, or any of a dozen others on the market to neutralize the chlorine in the water, just follow the directions, the balance of what you have is primarily for fish or water problems. Bromothymol blue is to treat a condition called ick, a skin problem. Multi cure handles a lot of fish ailments, but most would be more sucessfully addressed using specific meds designed for specific illnesses or ailment. Antibiotics are cheaply and widely available for fish diseases. Use a water test kit,$5-10 at your pet store, to determine the pH of the water in your tank after dechlorinating and use pH up or down to adjust to that which is appropriate to the fish breed you have. Water care involves a lot of chemistry and seems a little daunting at first. Just follow the directions on the containers and you will be fine.