Hi JJ, I don't know how you go about it, but I fill my MLT with hot water from the tap to speed things up a bit. I would hate to be lifting 10L of hot water that high. However, it you were just filling your MLT from a hose, then that would negate the problem. I currently have a 3 tier and am going to build a single tier down the track with a march pump to transfer liquids between the vessles. If you do build that style, I hope your mate is a good welder as there will be quite a bit of stress on that frame.
cheers
Browndog
P.S why don't you have your name down for the xmas swap slacker!