I am considering whether to convert my pool to a saltwater pool. The recent acquisition of a AquaLogic PS4 control system ended up coming with a SWG cell.
I downloaded some equipment manuals for new Jandy (Laars) gas-fired pool/spa heaters. The manuals for the Jandy Lite2 and another Jandy line both stated that the heater was for freshwater pools only and not for saltwater pools. The acceptable chemistry for both heaters stated that the TDS would need to be below 2000 ppm. http://www.jandy-downloads.com/pdfs/H0248900D.pdf
So I decided to call Jandy technical support in order to find out which heater line would be acceptable for a saltwater pool, since the manuals I was looking at indicated that these two particular lines were not suitable. The Jandy tech guy said that when the manuals said "saltwater" that this meant pools with a salt content of less than 6000 ppm. He said that Jandy considers pools with salt content of less than 6000 ppm as "fresh". I then asked him about the requirement to keep TDS below 2000 ppm and how this would be possible with the recommended salt level of 3000 ppm. He went away for awhile and came back with the answer that in order to determine the "true" TDS levels for purposes of following the water chemistry of the manual, that one should first test the TDS levels, then subtract out the salt levels, and then that would be the TDS levels used to determine whether one was meeting the 2000 ppm limit or not.
I must admit that, as an engineer, that this conversation did not leave me with a warm and fuzzy feeling. I think that I would need the verbal assurances given in the above paragraph to be documented in writing somehow. Especially that the "How to Order" page on the Jandy website for the heaters mentions several different metallurgies available for the heat exchanger tubes. Oddly, I can not find any reference at any internet sites that sell Jandy heaters that there is even an option to buy different metals for the heat exchangers.
I then asked whether my existing 23 year old Laars heater would be suitable if I converted my pool to a salt water regime. He said that my old heaters heat exchangers would have no problems in a 3000 ppm salt pool.
Maybe I should be hitting this question from the other direction. What material is suitable for heat exchangers and headers in a 3000 ppm salt water pool?