George, there is a water strainer located at the back of the basement compartments, behind the panel where the water pump is located. It is a fine screen filter/strainer. If you do not have a shut off valve before the pump, you will have to use a plug/cap to stop the water from running out from fresh water supply when you service the strainer, or you can service the strainer when the water tank is empty. I installed a 2-way valve before the strainer/pump to allow me to service the strainer without having to plug the line or empty the tank. It also allows me a port to winterize the water system. If strainer is clean, pump may need replacing. As far as the internal regulator, I believe there is one at the fresh water supply hook up behind the water manifold. I always install one at the water supply faucet to protect hose from high pressure. Have no experience with one behind manifold. Hope this helps. Frank.