Just came up with a pretty easy way to change small amounts of water more often, though it might take some work to install. Put a 5 gallon jug filled with new salt water above main tank with PVC running to the bottom of the main tank, or as far away from the overflow as you can get it,and put a valve on the PVC. On your sump, drill a hole right above your normal water level that you would top off or fill to. From this put a bulkhead on it and lead the PVC line to a drain or somewhere you can dump saltwater. The way it would work is when you opened the valve of new saltwater it would displace more water filling the sump higher. Because the new water is far from the overflow only old water would be going out the sump overflow. This system could even be automated by installing some kind of electronic water valve on a timer. It would also prevent an overflow if your topoff system malfunctioned.
One question though, how would you keep new salt water fresh over a 2 week period, lets say in a ten gallon tub?
Chris
One question though, how would you keep new salt water fresh over a 2 week period, lets say in a ten gallon tub?
Chris