Fish absorb a number of vital mineral through their skin and gills. Aqua One conditioning salts replenish natural minerals that are deficient in tap water as well as minerals that are removed from aquarium plants and fish. These salts will help to ensure long term health of aquarium fish while replicating conditions found in natural waterways. This product may cause a slight increase in pH and it is recommended that the pH is checked after adding conditioning salts Conditioning salts do not evaporate or degrade in the aquarium.