If your livestock is OK, suggest adding some premixed saltwater the next time you have to top off the tank. Since you would normally add fresh water to top off, this would raise your SG in a not so abrupt manner. Proper salt mix with the Instant Ocean mix that I use is 1/2 cup per gallon. Otherwise, remove some water from the tank and add some salt to that water, making sure it is thoroughly mixed, and then return it to your tank by pouring the new mix a little at a time into your sump. Add less rather than more to avoid raising the SG too high.