just through in some melifix it will make the skimmer skimm and it is good for your fish. many very large lakes have a salt content to them Profict example is lakes manitoba and lake winnipeg. Both lakes are in lake lakes but are concidered inlane seas you can smell the salt on the right day. The sand flies are bad but they are attracted to the salt that is on you after you go into the water. You can find quite a few clams that are found in sea water they have adapted to the very low salinity of these lakes. I my self have never measured the salinity of the lakes. Is there anyone that will check it out in the summer???