Looking forward to learning & sharing info. We have a 20x40 pool built sometime in the 1960s, and re-coated with pebble-tech about 20 years ago. 2 summers ago I redid all the bluestone around 1/2 of the pool. Next plan is to get rid of the old style copying with some bluestone + replace cracked concrete on the far side. While doing that plan on upgrading the plumbing. Dealing with a Raypack 206A heater that just had the heat exchanger go bad. Researching whether to replace just the heat exchanger or bite the bullet & replace entire unit.