The synthetic seawater made of ornamental fish type sea salt is suitable for growth and reproduction of all tropical ornamental sea fishes and other ornamental sea creatures. It is the ideal product for aquariums and household sea water aquariums. Direction: 1 kg of ornamental fish type sea salt is fully dissolved in 30 L of tap water or potable freshwater to form synthetic seawater with the same properties as the natural sea water(S≈30‰). It is the ideal substitute of natural seawater. It has the following features: It can be used for easy and quick preparation of synthetic seawater without the effect of inland contaminants.