This is developed by ourselves to make the best environment for the fresh water fish, it must be keeping mildly acidic water condition for long term. Advanced soil is 100% natural ingredients.Advenced soil soon drop the water pH & KH, creating close to nature environment in an aquarium. This allow you to have fish in an aquarium on the very day you set Advanced soil. *Basically, it is recommended to put the fish a week later after you set up an aquarium and keep water circulation. Advanced soil has granules that are denser than other conventional product. This prevents each granule from flying all over so that water soon settles down.