Ammonia is used in conjunction with other chemicals to kill and solve algae problems in personal pools. The correct pool water chemistry is imperative to keep algae of all kinds from growing in a recreational swimming pool. Algae has been known to cause illness to some swimmers.
Ammonia and Algae
The three most common types of algae are green (floats on the surface of the water), mustard (slimy yellow film on walls of pool) and black (clumps on tile grout and pool steps). All three require different treatments, so identify them based on these characteristics first. Green algae is the easiest to treat with chemicals. Proper chlorine balance in a pool rectifies this situation. "Superclorinate" the water at night with a 10 to 20 ppm (parts per million) ratio. The filter should continue running to catch dead and dying algae and you should scrape the walls of the pool to knock any algae loose. Ammonia is used in the next stage, where you place an algicide with ammonia as an ingredient in the water. This prevents green algae from returning after the superclorination has killed the algae. Mustard algae is harder to fight, and will not be as susceptible to chemical treatment. Do the same as with green algae, but also vacuum the walls prior to adding the ammonia-based algicide. Black algae is the most difficult, and will require an ammonia-based algicide after it is rid from the pool, but ridding it from the pool will most likely mean draining the pool and scrubbing the algae off.