My return pump was slowly leaking for about a weak and my neptune apex ato was replacing the lost salt water with freshwater. I noticed the tank wasn't opening up.well.today so i.went to the basement where the sump.is located and checked the salinity and it was a horrific 18 and it usualy stays about 34. I mixed up about 15 gallons of double strength salt water and added it about 5 galons at a time over a couple of hours which raised the salinity to about 21. I have 30g of water getting ready now. What is the best way to raise the salinity safety but as quick as possible?