angelfish/nitrate levels

Question
Hello. Earlier this year I had contacted fish deeva because my angelfish were passing away from high nitrate levels. It got better. Just recently the levels have gone up again. I have started to changed 25% of the water and had some start zyme and salt. Whatelse should I be doing again? Only one fish seems to be stressed at this moment, but I want to catch it before it gets really bad.

Answer
Hello Kelli!
I'm sorry to hear that your fish isn't feeling well. You can try the API Stress Coat and Stress Zyme. Stress Coat, has the healing power of Aloe Vera, is scientifically proven to reduce fish stress by 40% and heal damaged tissue.  It forms a synthetic slime coating and replaces the natural secretion of slime that is interrupted by handling, shipping, fish fighting, or other forms of stress.  Helps reduce susceptibility to disease and infection.  Helps heal torn fins and skin wounds.  Reduces electrolyte loss.  Also works instantly to remove chlorine, chloramines and ammonia from tap water.  Neutralizes heavy metals. Use when starting a new aquarium, adding or changing water and adding fish.
Stress Zyme is a biological filter additive containing live bacteria that improves the development of the biological filter and helps clean a dirty aquarium. The build-up of organic pollution in the aquarium inhibits the growth of nitrifying bacteria. The bacteria in Stress-Zyme keep conditions in the aquarium right for the development of the biological filter by consuming harmful organic pollutants. This speeds the development of the biological filter in newly set up aquariums. Stress Zyme keeps the biological filter working properly by keeping the aquarium gravel and filter clean. Water quality and living conditions are improved when Stress Zyme is used on a regular basis.

Each teaspoonful of Stress Zyme contains 300 million bacteria. These bacteria are in a dormant state and become active when added to the aquarium. Stress Zyme has a five year shelf life and does not require refrigeration. Stress Zyme is effective in freshwater and marine aquariums.

I hope this helps! :D If you have any more questions or concerns, feel free to ask!
~Sam