On Sunday, June 30, 2013 7:49:42 PM UTC-4, wrote:
Hi,

I've installed a large tank in the yard, above the height of my toilet water closet. I'm filling the large tank with water from a sump pump.

Problem is this:

The gravity feed is very low pressure, so the regulator in the toilet water closet doesn't function using the gravity feed supply. However the regulator works fine when using the city supply for water.

Is there anyway to adjust the regulator in the toilet water closet to work with very low pressure water supply?

I'm back, just read most of the replies.

What I ended up doing is taking the shut off valve a part (it was easy) and removing the large rubber rings that are used to quiet the water flow. I think that's what they're in there for. I left only the small one that actually shuts off the water when the ball arm is lifted to the top of the tank by the water height.
So the low water pressure works now and I've been using the system all month.
It takes about six minutes for the toilet tank to fill enough for another flush.
With the large rings removed I can hear the water trickling into the tank, but I don't mind as it lets me know its working okay.
Thanks for all the input.