Yup, just regular freshwater.
If you are losing that much per day, you might want to look into getting an auto-top off set-up going. It is almost 0 work for you, and it keeps the salinity perfect in your tank. Since setting up mine 3 months ago, it has worked perfectly for me, and not having to top off my tank is a wonderful thing. If you are ever interested in setting one up, just email me. My email is
Ry84@MSN.com. I set mine up for a maximum of $50, and as I said, it works flawlessly.