still confused about target FC

Lanailounger

Silver Supporter
Aug 23, 2016
39
Naples, Florida
I have read and reread everything but confused about target FC. Should I maintain a 4-6 FC or shoot for higher esp with swim season starting and hotter days. Still unsure of myself but so far pool water looking good.
FC 6.5
CC 0
PH 7.8 ( added acid)
CH 375
TA 80
CYA 75
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
11,470
Bedford, TX
L,

See this chart... https://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

In a Saltwater pool, with a CYA of 75 (round up to 80) then your target is 6 and the minimum you ever what to let your FC drop to is 4. So, technically 4 to 6. But... I suggest you shoot for something that keeps you from ever dropping below 4, so my "Target" would be 5 to 7, this gives you a little wiggle room.

I'm going to suggest that we change our chart to show the "Target" values for SWCG pool in the same format that we should the target value for Non-SWCG pools.

Thanks for posting,

Jim R.
 

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,292
East Texas
4-6 should do you just fine with a SWG with it's run time spread out over the pump run time.
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
25,179
FL panhandle
Here is the general idea. Minimum FC level is a number that you never want to drop below, ever. Target is a suggestion because most SWG pools will lose less than 2 ppm from the time the SWG shuts off to the time it starts up again. Any number above target is fine, whatever number is needed to make sure that the FC doesn't drop below minimum. It is safe to swim with FC up to shock level for your CYA.

In your case with CYA of 75, we round to 80, because the CYA test is logarithmic, so halfway between 70 and 80 is not 75. With CYA of 80 your minimum FC level is 4 ppm. Which means that you do not want your FC to be below 4 when the SWG starts up for the first time of the day. If 6 covers that then good. If not, then target 7 or 8 or whatever be plumber is necessary to make sure that FC is 4 when the SWG starts for the day. It is safe to swim with FC levels up to 31 ppm. So, you could safely keep you FC at 8 or 9 if you wanted to or needed to.
 

Lanailounger

Silver Supporter
Aug 23, 2016
39
Naples, Florida
I have been concerned about having too much chlorine for my cya, but it sounds like I don't need to be. FC has been running 5-8 all winter with cya at 80.
Thanks
 

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