FC level questions with SWG....

[lorngraves]

I did another full water test yesterday. I checked the CL/CYA chart in the stickies and it says I should have a target FC of about 9, min ~6. The pool calculator says for SWG FC of 3 is OK. Which should I shoot for? I don't use algecide so really want to prevent an outbreak. Though PB did leave 2 bottles of poly?? algecide..should I add any as a precaution? My water is crystal clear now after being slightly cloudy upon opening last Wednesday.

FC 7.5
CC 0
TC 7.5
CYA 80
pH 7.8, adding acid tonight
TA 130
CA 300
Water temp 62
Salt 3300

So what should I aim my FC for?

 

[JasonLion]

The chart in the stickies actually suggests 3.6 if you follow the comments in the foot notes relating to SWGs. SWG are able to run at lower FC levels than other chlorine sources, probably because of the shock levels of chlorine present in the SWG cell.

I recommend aiming to have FC be between 4 and 5 in the late afternoon/early evening (which is when FC is normally lowest). That gives you a little extra margin to handle unusual events.