I've always found that a mixture of sand and old rags gives the best fill (for weight and conditioning), I have never heard of a water filled bag. Freestanding "wavemaster" styled bags are water filled, but that's just the plastic base, for balance.
at the pcyc in the boxign room all the bags are filled with water and its easy to kick and stuff and i wanted to do the same thing at home
Ok this got me interested,and after a google I was able to find a bag that has a bladder filled with water in the center,and foam surrounding the bladder, all encased in non rip vinyl. or this one which looks better and can be purchased here in Australia from here I would say you would have to buy one buddy, you can get them for under $130. As far as filling it you would have to hang it and fill it with a hose. They weigh in at 50kg so make sure you have a strong place to hang it.
why water? what the hell posessed you to do this? anyway, i strongly recommend using rags, sand, straw, carpet faom, or a combination of two. i find that if it's for your own personal use a combination of straw and sand work the best because it makes things hard and you can adjust it as you go. if you use it for commercial purposes (or may use it for commercial purposes) go with the rags. it's nice for the new guys who's legs aren't very strong yet. Mullins
