Disney's 75G Tank Journal

[Lampshade]

I would add the full amount. A lot easier/cheaper/cleaner to find leaks with fresh water instead of saltwater. As you add rock/sand you will have to take some water out, but it's shocking how little water the rocks actually displace, they soak up most of it.

Nice setup so far, should do very well. I love that sump, should make life easy.