Just a couple of pennies for all --- one of the main reasons I started going to the 'pool sites' is this same problem. What I've seen is that the pools that need a new heat exchanger (in some cases YEARLY ) is the reliance on tri- chlor feeders with ~ NO water testing nor maintenance

Tri- chlor has a very low pH and it doesn't take long for it to become so low that the copper heat exchanger just gets dissolved by the acid water!

BBB is IMO the best way to care for a pool, but if you use tri- chlor - at least do as Carl says and spend 2 min a day to check the pool (and if a # is 'out of whack' - ADJUST THE CHEMISTRY ACCORDINGLY!!!) A heat exchanger runs ~ $1300 - is 1/2 hour per week of your time worth more than that???