Cold, SWG off, do you go to 7.5% of CYA for your minimum FC?

[needsajet]

Winter here, shut the SWG off yesterday. Since part of the lower FC/CYA ratio used for SWG is because of super-chlorination and other harsh reactions inside the SWG cell, should I now adopt the 7.5% bare minimum FC/CYA ratio? Pool will be open, running, no cover, and unused (by humans) for the winter. Before the water got below 60 degrees (15C), I was running 20% and 4 hours to deliver 0.5 PPM FC per day.

Thanks heaps for your opinion on this.

- - - Updated - - -

FC 5
CC 0
pH 7.9
TA 70
CH 350
CYA 70

 

[Jezza]

I have just done the same Needsajet- my SWG has been struggling to cope over the last week when the temps got really low especially in the morning. I just chlorinate now with liquid chlorine until spring time using the non-SWG FC/CYA ratio. I know your at a higher CYA- but what I do is just let the rain do the trick- draining the excess the water to bring the CYA down from about mid Autumn. I'm currently at 50 CYA with the rain we have have over the past month or so.

 

[pooldv]

After I turn off my SWG and switch to bleach I dose FC to 10-12 and test once every week or two (or 3 as it gets colder) and add another jug when it drops to 7 or 8. One jug is 4 ppm in my pool. I like to let it drop below 10 so I can test PH. Otherwise, I would keep it higher. My CYA has usually dropped to 70 by fall.

 

[needsajet]

Thanks, Jezza and pooldv. I'll remember for next year to let my CYA drop as well. Dumped a jug of bleach in yesterday to bring it up.

That was my first bleach! $1.19 for 1/2 gal (2L) of 4.2%, arghh. Grabbed it at Coles (grocery) to save a trip to Bunnings (big box hardware) for high-test, but will grab 12.5% next time I'm there.

That's $2.00 per 100 g chlorine vs. $0.69 at Bunnings. Maybe I saved $1.30 on petrol. Gotta love bein' frugal. (ya tight-..., mate)