OK I may be late on this but I saw a awesome check valve at the LFS today. The shape was exactly like the check valves we know from HD or Lowes. But it was clear plastic. The valve was like the stopper in the toilet tank(the flapper). The stopper was connected by a plastic/rubber strip so no metal or spring parts at all. Get this, the pipe inside the valve was at like a 45 degree angle so it would shut w' any back flow. And I could see by having the rubber connecting the stopper it would be less resistance against the pump pushing up. They had all different sizes. 1. it is clear so I can see if it is damaged. 2. less restriction against the pump 3. same price as regular check valves 4 no metal pieces to wear out, rust, get stuck I think we have a winner. I'll email the LFS to get the mfg to see if they are in AR. I just thought that was the darnedest thing. One I get them and plumbed I'll give more feedback.
Marcus - I have used the check valves that you are talking about for several years. I have not had any problem with calcium build up. I do have a problem with cavitation from a lack of strong enough back pressure. I posted a thread a month ago about it without any successful answer to the problem that I am having. The cavitation does has not been enough to let enough water back through the check to cause any problem as of yet, but sooner or later the power will go out for longer than the episodes that I have had to date. http://www2.razorbackreef.com/old/phpBB2/viewtopic.php?t=70
