need a "low-preasure" preasure tank

[bill]

I have a rain water collection system, with the supply barrel 4' above grade. I get decent pressure for the garden hose attached to the valve at the base.

I set up some "leaky hose" (the black porous stuff) between the rows in my garden but the pressure isn't enough to force enough water through the walls of this specialty hose. The kicker is that this hose should only be supplied with about 2 lbs. of water pressure. (Too much pressure and the water sprays out instead of seeping through the walls of the hose at a slow rate.) Any ideas how I can set up a deal somewhat like the pressure tanks used with wells, but at the appropriate pressure. (Yeah, I already thought of putting a water barrel 15 feet higher, up in the attic, and pumping the water up there, but the risk of water damage and "I told you so" from my wife has buried that goofy idea.)

Thanks.

[Speedy Jim]

The tank at 4' elevation gives you almost exactly 2 pounds (PSI) of pressure. (In very round numbers, figure half a pound per foot.)

There will be some reduction in pressure at the hose, depending upon the pipe size feeding it and the flow rate.

Jim

[ares]

I don't remember, but are you supposed to put a cap on the very end of the hose so the pressure builds up in the hose so that it will go through the pores? ares

[PAUL100]

Are you sure about the pressure. from what I have been reading it should be about 30psi.

[David Efflandt]

You get 1 psi for every 2.31' of water. So if your tank is 4' above the hose and you have more than 8" of water in the tank, that should give you

2 psi (assuming the hose does not have much pressure drop at low flow). Maybe you are mistaken about required pressure.

[Harry K]

Speedy is correct, it is .455 psi per foot.

Harry K