[Albertan22]

The sump itself likely won't help with your salinity issue; however, it does give you the opportunity to incorporate an auto top off system. If you can manage it, try to build in room for a top off reservoir. Maybe you could put something next to the stand? I used a narrow blue recycling bin (approximately 2.5 gallons), put a maxijet 400 in the bottom, used clear tubing to plumb water to the sump, and used a float switch system I found online. The whole system cost me a little over $100 (the float switch being the most expensive component). For my setup, this gives me about 3 days of stable water/salt levels. In a system your size it might last a week or more.

The nice thing about a system like this is that if you simply get some extra tubing, you can set up a larger reservoir (like a garbage can) for temporary use if you ever leave town. That way you don't have to worry about friends forgeting to add ato water.

If you do set up something like this, be sure to account for siphoning from your fresh reservoir to the sump. Keep the tubing out of the sump water, and tie it higher than the water level in your reservoir or it will siphon down to that point (a lesson I learned the hard way).