Show ocean water for life I 1 NL necessary for sea water has been studied with I 1 great care and we know the thi things n 9 s which are to be found in it these include magnesium sulphate and calcium sulphate also iodine and salt salt is the chief thing which can be taken from sea water it has be been en figured that one cubic mile of water in the atlantic ocean contains tons of common salt think of how many billions and trillions of tons of salt there are in the oceans of the world people need a certain amount of salt for good health but we should never worry about using it all up one small bay of the ocean has enough salt to last the human race for thousands of years it would seem a simple thing to provide homemade home made ocean water for ocean fish in an aquarium we might suppose all that need be done is to put fresh water in the tanks and add the salt and chemicals which exist in ocean water that has been done but when ocean fish were placed in the water they died soon afterward men who take care of aquariums know what to do however in a tank of homemade home made ocean water a small amount of real ocean water is poured the real ocean water should be about one tenth of all the water that goes into the tank inside of a week all the water in the tank will be alive salt water fish can live in it and keep their health certain plants as well as fish will live only in ocean water many kinds of seaweed grow in salt waters of the world water plants of a number of kinds are found in lakes and rivers and often we call them seaweeds yet the ocean is the place where true seaweeds grow |