constant drip with salt water??

[Alberta-newb]

Are you looking at dripping saltwater in as a continuous water change or are you talking about top-off due to evaporation? For a continuous WC the most effective way (in my opinion) is to use a double-head peristaltic pump (dosing pump) that way water in is equivalent to water out. If your talking about top-off, you definitely don't want to be adding saltwater, usually just fresh (unless you're trying to slowly raise SG.

Francis