I have a standard 2.5 gallon, and I use the hose that came with my gravel vac. I just don't use the gravel vac itself. I put the bucket on the floor, and create a siphon from the tank to the bucket. When I refill, I put the bucket on top of stack of books next to the tank so it is higher than the tank. Then I just do the same siphoning from the bucket to the tank, and I hold the end of the hose against the glass so it doesn't disturb the substrate.