You can do that, it will work. I happen to have 5g jugs which is nice and easy. What I used to do is lend my unit to my girlfriend for a few days instead of hauling water to her.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.