To mount the water tank, take a piece of wood about half an inch thick, and cut two holes in the wood that are slightly larger than the diameter of the tank you are using. Cut the two holes apart from each other to make two blocks with a hole in the middle. Then drill two small holes in the bottom to allow you to mount it on the frame, just in front of the mop L-brackets.
Now to control the water flow, hold a paperclip over a flame to heat it up - once it is very hot poke about five holes in the tank (all in a line, and spread out). Make one more hole about 60 degrees above the others to allow air in the tank. Then just put the plugs in the ends and slide it in the wooden brackets. This was one of the things that I didn't have much time for, so for now just turn it manually to control the water flow.