I am on a shared well with two other homes. My home is at the end of the main water run about 200 ft from the well. The well has 3 full size pressure tanks and most of the time I have 55 psi of water pressure but when my next door neighbor's holding tank fills my pressure drops to 15 psi. I don't have any holding tanks or pressure tanks on my lot. Without spending a lot of money what's the best bang for my buck to help when my pressure drops to 15 psi.

I'm not following you on this one. Your neighbor has a well with 3 pressure tanks. What is the holding tank for? Also, who actually owns the well?

You could certainly put a tank on your property and put a check valve "in front" of it, but that would only be good for 10 gallons or so. Once you dropped the pressure in that tank, you'd be out of luck until the system pressure got back up.

Are you using the term "holding tank" for the pressure tank? A well can only supply so much water at one time and if others are before you on the line, you will have this issue. If there is enough volume, you could use a booster pump or install a holding tank and then a booster pump. Only other solution is to put in your own well, figure $5K+ depending on depth and type.

You have a community well supply with a separate well house/pressure tanks for storage, correct? Install a backflow preventer (URGENT importance) or at the very least a check valve at the water inlet of your home. This will prevent backfeeding of your water supply. If this is what is happening (backfeeding) the well system is not up to code and your community has a serious potential problem. All the homes on this well system are required to have such an apparatus to prevent backfeeding and worse a potential "Vacuum" problem which could affect the water heater and any pressurized storage in the home.
I would have a licensed "master plumber" inspect this community well system ASAP.
RJ

Thanks for all the feed back. In my first posting I listed that when my neighbor's holding tank fills my pressure drops to 15 psi. The 3 homes are 45 years old but my next door neighbor's home was remodeled and was required to install, two large holding tanks 6ft tall 6ft wide for fire plus a third tank 8ft tall 6ft wide as a holding tank. The system also has a pump motor that keeps his pressure high and a 80 gal pressure tank. I was wondering if I installing two of the 80 gal. pressure tanks on my property if this would help. I was think the first tank at the front of my yard where my line enter my lot to help with the yard pressure watering and the second one near my house where it feeds the house. Could this minimize the pressure drop. I only get low pressure less the 80% of the time but it's hard to shower with 15 psi.

I think I see your problem. Your neighbor with the holding tanks must be putting a lot of water in. When he runs water for, let's say three or four hours, you get down to what the pump can deliver since it would empty the pressure tanks. Why wouldn't your neighbor simply fill the tanks at night when no one else is using water? Then it would make no difference. And even though the three tanks a HUGE, the two tanks for fire should not have to be refilled to any great degree unless they are leaking, so it would only be the one tank he uses for water that would need refilling.

Don't waste your time buying pressure tanks. That would somewhat solve your problem, but once you emptied the tank, and that wouldn't take long, you'd be back to 15# pressure. If you can't get your neighbor to fill his tanks during more convenient times, then consider buying a holding tank of your own. Two or three hundred gallons would probably do fine. Then buy a pump and a small pressure tank and you'd be in business.

I still wonder who owns the well system.

Read RJH's post carefully. He has some good points. You definitely need a checkvalve. If you do buy the large pressure tanks, then a checkvalve would HAVE to be added. Otherwise, your neighbor would simply empty your tanks when he uses water.

I agree with jlisenbe. The holding tanks for fire should only need to be filled initially. The booster pump the neighbor has is exceeding the output capacity of the community well. It may help to, be diplomatic, and see if they can cut the booster pump pressure back and do as jlisenbe suggested, fill at night.
I refer to my previous post. These issues need to be addressed.
This is such a small community well (3 homes) that it is probably owned by the homeowners association. Larger community wells will typically be governed by the locality or county government.
RJ

Thanks for your input to my problem. I'll contact a local well service provider and verify that we have the proper check valve in place and plan out a reserve water tank or pressure tank to fix the pressure drop.
I'll also see if my neighbor can add a timer to his holding tank fill valve. I know that it just kicks on via a float switch.
Thanks for the information it helped...

Just my two cents. Since your neighbor has the holding tanks, you could ask them to install a restictor (even a ball valve on the line feeding the holding tank would work) to restrict the water entering the holding tank. They would need to restrict the water enough so that the pump could keep up with the demand of your house, and still fill the holding tank. This way, his tank is still being filled, but at a slower rate, so the pump could keep up to your demands. Just a thought, but would definitely be worth a try, as it may be a cheap simple cure to your problem.

Does this make sense guys?

Installing a pressure tank will most likely do absolutely NOTHING to help your problem. The pressure tank works in conjunction with the well switch to turn the pump on and off and have a certain amount of water in storage so the pump does not run all the time. You are too far from the well house to benefit from a pressure tank. Your neighbor has a holding tank (no bladder) with a repressurizing pump after it for higher household pressure. What you need the well man to determine is the output of the current well, GPM, pressure and how this affects each homes demands. What might be the solution is to have the neighbor set the float switch higher so their holding tank will fill more frequently but require less DEMAND when it does.
Example: If the float switch on a 1000 gallon holding tank is set at 150 gallons and the well supplies 30gpm it takes 28 minutes to top off the holding tank. If the float is set at 800 gallons it only takes 7 minutes to top off. Hence less water demand from well and community, well pressure is maintained at higher end. All the water from the holding tank is drawn from the bottom so fresh water is constantly replenishing the holding tank.
RJ