
The PC are 2 liter soda bottles, so it can hold about 3L total (some space for air, otherwise range is terrible). I threaded metal pipe onto them, and they do not leak enough to be a real problem (especially once I put a pump on it so I can pump every now and then to hold pressure):

The SC-like adapter is just a piece of .5 inch PVC and a hose coupling. It is not glued, so it fires backwards when the PCs are about 2/3 full. This does in a way prevent it from over pressurizing.

Performance is much better than my other APH, probably due to the better PCs. It holds twice the water and can fire for quite a long time on most nozzles, and does not sputter. The riot blast on this is terrifying.