I have just (properly) buried plumbing to allow me to replace the standard "cheap rubber hose" filter backwash discharge, rolled out onto my driveway, with much better solution of permanent solid rigid pipe run to an appropriate area.
I have run 1.5" PVC to the pad, ready to plumb into the sand filter discharge, but I've reached a point of confusion. Currently, the filter has a nice little clear section of plastic(PVC?) that the cheap rubber hose clamps onto. Watching this "window" is how I tell when the backwash is running clear, ready for rinse.
I believe I should replace that little clear piece intended for rubber clamp on hose, with a similar solid clear piece that can be glued into typical schedule 40 PVC, however, I can't find such a piece. The people at the local pool stores think I'm crazy to even think such a thing exists. I know clear (pvc glue compatable) check valves exist...why can't I find a 3"-6" long clear plastic 1.5" pvc part? Of course, I guess I could buy a clear check valve, but I don't really need the check valve functionality.
Based on structural support for the pipes, I'd rather not have my discharge terminate at the filter with a piece of flexible tube, which seems to be what the local pool shops think I should do.
Am I thinking about this wrong? Where can I find a short piece of clear, rigid, 1.5" schedule 40?