water is likely your best bet from the bottle. Are you in a position to purchase and use an RO
system to make water? In that 110g tank, you're gonna have to deal with 20-30g a month for water changes and evaporation. I'd look into an Ro
if I were you.
Also, if you test your tap water, you may find you can get started with that anyway and upgrade shortly thereafter to an RO
. You can find them for less than $150 I think. Compare that to the cost of filling the 110 and maintenance.
You doing fish only or reef?