Quote Originally Posted by mkamp1515
Thanks. I am going to bring up the chlorine by shocking it. I talked to the chemistry/service folks from my pool builder and he indicated my CYA was too low for the heat we have been having here. I will bump up my CYA and shock the pool and have more shock on hand for my housesitter to put in if necessary. That should help prevent any algae blooms.
Mike
Most SWG manufacturers recommend the 70-80 CYA level that you have now moved to. The reason is that the salt chlorine generation cells operate more efficiently if there is sufficient CYA around to "tie up" the chlorine as fast as it is being generated so that it does not build up and slow down the generation process.

If you are going to keep your CYA high at 70-80, then you need to keep your FC at 5-10 ppm in order to have adequate disinfection and prevent algae. However, having your CYA at this high level along with the required FC level will have you lose more chlorine per day than you would at a lower CYA level (and correspondingly lower FC level). See Ben's Best Guess CYA Chart. On other forums specific to SWG, some people think that Ben's chart is overkill and not as necessary while others think it is. So, if you want to play it safe, go with Ben's chart (which is around 7 ppm FC). If you want to play it loose, you could go with lower FC, but I would not go below 2 ppm FC in any case since that it is the limit of disinfection protection -- probably stay with at least 3 ppm FC if you go this "riskier" route (which most SWG users would not call risky).

Along with others, I am trying to determine what the true proper chlorine levels are to prevent algae and to shock (kill) algae both in non-SWG environments (where Ben's table has been reliably proven) and in SWG environments (where Ben's table is a little controversial).

Richard