A one-gallon pressure tank from soda bottles

This is my one-gallon pressure tank, sitting on Maxwell House instant coffee jars:

• Inlet (left) and outlet brass are quick-connect fittings. Inexplicably, I used teflon tape.
• The hose is 5/8" ID, from True Value, pieces cut about 3" long.
• The hose clamps are #8s, less than a buck apiece from Lowes. They don't have long tails, the #8s, on 5/8" hose.
• The tees, 63 cents apiece, from United States Plastic Corporation.
• The white fittings are three female and one male nylon GHT-to-5/8"-hose-barb fittings, from US Plastic Corp. The females came with eye-catching red hose washers.
• The green fitting is a shut-off valve, similar to this one.

No leaks. In particular, no leaks at the soda bottle slash hose fitting connections.

The outlet end hooks up to a garden hose. I've been using a 50-ft shrinky hose, as that's what I had. But 25 feet would be more than enough, as the pressure tank hooks up to a sprayer on a cart, and the tractor moves the cart.

The inlet end hooks up to the sprayer. I cut off the sprayer wand and most of the hose, and used a GHT-to-3/8"-hose-barb fitting to connect sprayer to pressure tank.

It's embarrassing to call the assembly a pressure tank, really. It's too small to be effective. But it was built for test of concept, and it worked. Between uses, the soda bottles sit empty, or rather, full of air. When I hook up the sprayer and turn on the pump, outlet valve closed, the bottles fill with water, compressing the air in the process. It does what I need.

I have a 25-gallon sprayer. With a 20-gallon pressure tank I'll be almost doubling the capacity of the system.  The pump on my sprayer is a low-volume unit that shuts off at 60 PSI. The pressure tank helps to compensate for the low output of the pump and the resulting low average pressure in use.

My one-gallon pressure tank works. But it needs to be bigger to be effective. So I'm saving soda bottles. It would defeat the purpose to go out and buy them.