Salt?

[Iron E]

Okay. This might come close to the "stupid question" category. I read that I should have my top-off water heated to match the tank water, aerated, pre-balanced for PH, hardness, salinity, etc. This all makes sense to me except one thing. When topping off to compensate for evaporation, if you add pre salted water, aren't you increasing the salinity? Does the salt evaporate too? It would seem that you would end up with a tank full of salt eventually.

Sign me... Duh!?

[CarmieJo]

Good question! You add fresh water for top off because the salt doesn't evaporate. The parameter matching you mentioned is for your SW.

[poppin_fresh]

Like Carmie said, the only thing that "evaporates" from your tank is pure H2O, therefore its the only thing you need to replenish to account for evaporation. Uptake in minerals, etc is another matter and is controlled by water changes and supplimenting.

As far as heating, aerating, PH, etc. its not critical unless you are pouring in a lot at once. IMHO if you are only topping off 1% or 2% of the tank at a time, through out the day it will have little effect. Dont stress about it.