So im planning a Saltwater tank in the near future. i have a question before i just jump into it. When you do water changes you have to put salt back into the tank im aware of this. However when you do top offs do you just add freshwater? Reason i ask is my tanks lose a TON OF WATER every week. i do weekly to bi weekly water changes and in a week my 65 will be down almost an inch. i have glass tops on them that just drip all day everyday lol. so i was curious about Saltwater... May be a dumb question if it is im really sorry for wasting your time lol

I have the same problem with evaporation, I read somewhere it's partly to do with surface agitation and lighting. Mine's open top and I lose around 15-20 Litres a week on a 240L tank. Just keep topping up with fresh R/O water (the salt does not evaporate ~ Salininty will increase mildly) Having a glass top is supposed to help though.

Oh okay thanks a bunch! i think it may have to do with my lighting i have 146 watts of T5's ontop of the tank as well as two Hob filters... that makes alot of sense with Surface agitation.. hopefully i dont run into that with the saltwater LOL.