I bought a mountain cabin last year in N. GA for occasional use. I installed a shutoff valve behind the water tank so when we are not there the tank is still pressurized, but I don't worry about burst pipes. Water pressure was great for about 8 months, then the water pressure dropped at all faucets. So far I have removed the large water filter from the system, which I was concerned created blockage, no change, then I had well guy install new 1 hp pump in my 300ft well still no change. I tested the water flow and pressure before it enters tank - it is great. The water tank has bladder. I tested the air pressure with water tank empty - it was 30lb. The pump turns on and off at 40 and 60 psi. The water tank is only 3 years old... I am stumped at what to do next. Should I change the water tank next?

The water tank has bladder. I tested the air pressure with water tank empty - it was 30lb Your bladder tank should be charged at 38 PSI.
If your pump furnishes 6o PSI to the bladder tank what'[s the PSI inside the house?
So you have a filter, what else is there before the water enters the system? What's the pressure drop between the pump and the house? Back to you, Tom

Out of the water tank - I have about 6 ft of 3/4" new cpvc pipe and (4) 90 degree elbows then I have a small in line filter. I removed the filter and turned the water on and it just trickles out of the filter housing - similar to pressure at faucets. Would the 8 lb pressure lacking (30 vs 38) in bladder impact pressure to that degree? When I drained the water tank (not the whole house line) I got about 8 gallons of water out - if that means anything. I looked at home depot for same size tank and they call it a 19 gal tank.

As clarification - the pressure from the well to the tank is good - the pressure gauge and switch is attached to the manifold below the water tank.

What am I missing here? If you have 60 PSI from the pump to the filter housing and just a trickle coming out of it then it looks like a no brainer to me. Simply remove the filter!

Would the 8 lb pressure lacking (30 vs 38) in bladder impact pressure to that degree? No. but the correct setting is 2 PSI under the cut in point on your control box. This is done with the breaker off and a cold water faucet open to bleed off the pressure. Good luck, Tom

Getting 8 gallons out is likely about right.

Is this filter one of the cartridge types such as can be found in Home Depot, Lowe's, etc? If so, they are cheap. Replace it, or take it off and clean it out. It probably has a bypass valve on top and that could, I suppose, be "crudded up". Be sure the valve is fully turned to the "on" (or whatever it says) position. Or, as Speedball suggested, take it off and see if the problem goes away, which it almost certainly will.

Replacing it is probably where this will all end up, which makes it sad that you spent that money to put in a new pump.

One more thought. The cutoff valve you installed. Be sure it is fully on. Try turning it off/on several times. It could be clogged. That's the first thing I thought of when I read your original post. Pretty easy to disassemble and inspect/clean out.

The old water pump was really old and ready to fail, so I am OK with that. The water filter housing and cartridge was just installed, (home depot unit). I removed the cartridge and left the housing holding the cartridge off so , the filter itself is not creating blockage. The manifold for tank and the tank and the shutoff valve are I guess the areas that may be problem. Can there be blockage in the tank - should I swap tanks - or put 8 lb of air in first before changing tank?

Changing what tank? Am I going to hafta say this twice?
If you have 60 PSI from the pump to the filter housing and just a trickle coming out of it then it looks like a no brainer to me. Simply remove the filter
I just got to be missing something if you don't think this is a solution.
You said,
the pressure from the well to the tank is good So why are you concerned with the bladder tank and its charge? And what's this all about?
The manifold for tank and the tank This is the first time I'm hearing about two tanks. Please explain? I just got to be missing something if we're not even on the same page. What is it? Back to you, Tom

Handy, if, when you remove the cartridge housing and the cartridge, and then get only a trickle of water from the filter unit itself, then either the filter unit is clogged up, or something is wrong "upstream" of the filter. So simply remove the filter and see what kind of flow you are getting from the pipe going to the filter. If you get good flow, then the filter has a problem. If you don't get good flow, then you have to start working back to the tank. The shutoff valve will be a suspect. Doubtful that the tank is the problem, though it is possible.

Again. Start with the filter.

I think the reference to two tanks was a typo. Correct??

Thanks - all for the various suggestions - I found the problem. I replaced piping and shut off valve between the tank and the filter housing. It turns out 2 small pieces of gravel each the size of a small small pea , plus some other debris was blocking the pipe by the shut off valve. I am stumped how such coarse pieces made it through the well pump screen. Perfect waterflow now.

Glad you're all fixed up and thanks for the update, Good luck, Tom