In a message dated 8/10/01 10:07:07 AM Eastern Daylight Time, jtouga1@… writes: << I add about 1 cup of instant ocean to 70 gallons of water. But I vary this. Some weeks ill make it saltier and others weeks wont add any salt. This immitates their natural environment. Estuaries never have a constant salinity. Julie Once you add salt it is there to stay. Wether you skip a week or six weeks the salinity level will not drop. Even when the watyer evaporates the salinity level will usually stay the same. The only way to lessen the salt level is to do a complete water change. I use a hydrometer and keep the salinity ( specific gravity ) at approximately 1.020 to 1.023. In reference to an earlier statement, by Jonathan, about Instant Ocean burning or irritating turtles could probably be true with any salt. It is never good to add salt straight into the tank, especially with the turtles in there. It is best to thoroughly mixt the salt water in another conatiner and add it to the tank/pond/habitat without the turtles present. Jimmy