Plumbing Fittings

        Above Ground:
                PUMP: For connections to, and from the pump, I like to use the black fittings in the picture above. They are threaded on one side, with a thick rubber O-ring that compresses against the pump housing. While every other type of fitting used can, and usually does, eventually leak, these never have. When you consider that each leak will probably cost you, in excess of $120 easily, EACH TIME, the extra $20-$30 you only pay once, is money well spent.  
                            Pipes Coming Out of the Ground & Connections to Back Wash Valves: When I am replumbing, I like to use the white fitting, in the picture above, to attach the lines going into, and coming from, the backwash valve. (The filter side already comes with unions. This allows the Back Wash Valve to be removed for servicing of both the filter, and the Back Wash Valve Itself. (Note: if you purchase a couple of extra unions, if you need to replace the entire valve, you will have a quick replacement.) Same with the pipes coming out of the ground. If there is a repair that needs to be made to valves, or because of leaks, broken pipes, melted pipes, ... you will have a replacement fitting that you can use without having to dig, or "layer" your plumbing fittings.
2 - Way Jandy Valve
                            Valves: For all Valves I like to Use "Jandy - Never-Lube Valves" like the one pictured above. They come in 3-Way, and 2-Way. I try to get the largest "Interior" dimensions possible, i.e. to join 2" pipe, I use 2" "INTERIOR" dimension valves (2 1/2" Exterior) rather than the 2" Exterior dimension valves. Jandy also makes a "Check-Valve". They, also, are of highest quality, and seldom fail. If they do, the essential parts are replaceable.