Changes in Pool Math app targets?

[BowserB]

I just noticed after a recent set of tests--following many inches of rain--that the target ranges for two Pool Math items changed. Example FC is now 2-7ppm. pH is now 7.2-8.0. If you look at my latest test, it's right after the rain finally stopped and I shot from the hip pouring some Muriatic Acid and liquid chlorine in as a stop gap. After this test, I added baking soda and filled a sock with CYA. I also dialed my IC40 down from 40 to 30 for a couple days.

Anyway, I wondered whether I missed an article on why 8.0 pH is OK when it used to be that 7.8 was the target limit, or why the target FC range has increased on the top end. Has "climate change" produced a new chlorine-resistant algae? BTW, for any prospective new pool candidates, I'm still hoping to get to the point where I spend as many hours using my pool in a year as I spend maintaining the pool. I know...it's like wanting to break even at VFW bingo, but it's still a goal.

 

[Texas Splash]

Good morning Browser. I suspect what you're seeing are simply changes in the "Acceptable Maximum" number as opposed to the "Ideal" ranges. The far left (min) and far right (max) can sometimes be adjusted based on various factors. Sometimes it's to accommodate a variety of pool types and conditions throughout the year. We still shoot for the "Ideal" range, but on occasion the other numbers are permitted.

If you still have questions, perhaps @Leebo can explain if I missed something.

 

[Newdude]

We added a target range for SWGs 2 winters ago because SWG pools swing too, albeit usually less than LC pools if any production is during the day.

Poolmath treats reccomened range for FC as between minimum and high target so it'll say 2- 8 or 3-10 (etc). Use the chart though and steer WAY clear of min at your low FC point in the day. The 2 or 3 in poolmath is just letting you know where the cliff is that you want no part in seeing closeup.

Anyway, I wondered whether I missed an article on why 8.0 pH is OK when it used to be that 7.8 was the target limit,

We recommend Ph in the 7s so technically dosing at 7.8 is doing so 'early'. Over time and road tested by gazillions of SWG TFP members, we've found it often hangs at 7.8 longer than the lower values so the 7.8 is actually now preferred by many of us.

Ph is a long term concern anyway. If you dose early then your pennance is the next dose will be earlier also. If you dose a few days late, or even a week late at 8.2, no harm is done.

 

[BowserB]

Thanks, guys. I restocked muriatic acid, CYA, and baking soda yesterday. Unusual weather hasn't helped, with treated water going out to the street and storm drains with recent rains. Now I see we're looking at two rounds of storms this afternoon and overnight. Not much point in fixing the chemistry this morning!

 

[Newdude]

Not much point in fixing the chemistry this morning!

Just ensure the FC can handle a 10% dilution with a several inch storm and keep it mixing.

I caught mine throwing a low salt alarm 7 or 8 times last year, even with my 24/7 operation. If the self check hits before the rain water has been stirred up, the cell will shut off for 12 hours until the next check.

Another reason the old '5' single target for SWG at 70 CYA had to go.