Water is a pain. Too liquid. Even though water is compressible (noticeable up around 2500 PSI) for our purposes it isn't. Constrain it too much and things explode.
Water in a media with a decent water holding capacity is really good. I have access to some specialty peat moss that has been treated for a special purpose. It does well when mixed with water.
I'm going to grab a bag of peat moss next trip to home depot and compare it to the stuff that I'm using.
I'm on the second summer with the same stuff I used last year. However at some point it's going to be come a lead hazard.
At this point the complete fixture ready to shoot is at about 90 pounds. Another 10 or so of water can be added if necessary.
The belting on the front works really well but has to be attached properly and I don't yet know what properly is.