I found your website online, and was really intrigued someone was talking pool sense, so thanks.

I have had an in-ground concrete/plaster pool for about 6 years now. It is about 34,000 gallons and located in the Denver area. The original design included a Jandy salt generator. I have gone thru probably 10 sets of heaters/heat exchangers in this time period, but no one can seem to pinpoint the problem. I keep my water pretty well balanced, at least to manufacturer specs, and don't have any issues with crappy fill water (i.e. high alkalinity). When tested (supposedly) for electric current, the water showed only a very, very minimal current.

Last year, we switched heaters from Pentair to Raypak, and still have problems. I finally gave up on the salt system, and started using dichlor, and have still experienced exchanger failure/leaking. We just pulled out the heat exchangers from the 2 heaters, and they did not show signs of any bad water chemistry, but still had holes or cracks in the exchanger tube(s).

Do you have any ideas what might be causing this?

Also, interestingly, I never had any issues with algae while on the salt system, but this year I have battled wall stain algae. I'm not getting why the same level of dichlor chlorine can't seem to fight off the algae like the SWG? In your opinion, what is the best way to shock the water now, and to what level, and using what product?

Thanks for your time and help.


Test kit is a Taylor K2005 (used the same style for 6 years). Test results:

Chlorine: 1.5 (almost consistently kept between 1 and 2)

pH: 7.5 (we added an acid feeder last year, and it reads 7.6; the pH has always wanted to run higher with this pool. I have never stopped adding acid just to see how high it wanted to go, but the highest I ever read was a little over 8)

TA: 85 (alkalinity is always between 80-100; I would have to add alk. up to get it higher; it usually wants to go lower, but typically remains fairly stable at 80)

Calcium: 220 (calcium wants to go lower, but only once have I read it below 150; I add calcium flakes probably 2-3 times year)

CYA: 20 (haven't added stabilizer for about a month now)

I test my water at least every other day for chlorine and pH, once a week for alkalinity, and once every 2-3 weeks for calcium). I use chemical-company chemicals, not store-bought.

The original install did not have an anode, but we added one last year. It has not degraded much since last year. The circulating pump is a 3 HP, we have 2-400K btu heaters, and we have the largest Pentair CnC+ cartridge filter tank. The pool is free-form, so we do not have a robotic cleaner. It is about 100 feet or so from the pool equipment to the pool. We run the circ pump 24/7. 2" lines between all the equipment. Hopefully, that covers most everything.

Ideas?