Any stones which contain lime or metal are toxic to fish. All rocks should be rinsed with boiling water before being used. Without preparation tapwater is unsuitable to use in aquariums. Your aquarium or dealer will be able to advise you on water conditioners to remove chloride, fluoride etc from the water. Plants are essential to the environment of your underwater world as well as decorative.
Plants enrich the water with oxygen and also provide hiding places for the fish.
In the beginning fast growing plants should be placed in the tank. Before planting remove all frayed or sick leaves. Make a hole in the gravel and insert the roots of the plant and cover. The most important equipment which you can purchase for your tank is a filter system. This will save you a lot of work keeping the tank clean.