Going against the tide here I think... but depending on your calcium levels in your salt mix to start with, you may need to supplement. For example, if you want to keep your Ca
levels at 380-400ppm, and you find that your freshly mixed salt water is mixing up at 340-360ppm, then you could do water changes until the end of time, and it's never going to go above 340-360ppm. The key is to know what the levels are in your PWC
water, and what they are in your tank.
As others have said, a drip system in such a small tank is probably more trouble than it's worth. You'd probably be better off using any of the 2-part Ca
supplement systems out there (B-Ionic, C-balance, etc). I use C-balance at the moment and have no issues with it. Occasionally when my Ca
creeps a little low, I bumb it back up using Kent TurboCalcium. I keep my levels between 380 and 400ppm.
If you do use an additive though, be sure and TEST for both alkalinity and Ca
AT LEAST weekly. I'd do it more often when first starting out. Many people have the tendancy to think "more is better" and it really isn't. Used to excess, the stuff can whack out your alkalinity and salinity. Just start out with what the directions say, test periodically, and adjust your dosage if you need.