What is consuming chlorine?!? SWCG can't keep up. Been SLAMing. Crystal clear pool now. Never algae on walls .

[TaylorN]

Note that chlorine degrades in the sealed bottle and so heat and time also “consume” chlorine so don’t get too confident in the cover.

Interesting point

 

[TaylorN]

I tend to keep covered pools in the 50-60 range and FC accordingly in the higher side of target but that's just my rule so I never get into trouble when the FC slips more then usual for some foreseen reason which went uncalculated.

That's a nice conservative approach

 

[TaylorN]

The point of using the chart was to explain the relationship of FC and CYA levels and corresponding HOCl level.

Stop overthinking. Read this article and follow the recommendations of the tool on the page to maintain your FC...and never let your levels get to "minimum." Link-->FC/CYA Levels

Again, you are overthinking it. It also depends on the type of cover. I have a solar cover. My FC demand when covered is about 50% of my covered demand. It is easier to not worry about how much the cover does or does not impact anything. Test daily, dial your pump time and % output to keep your FC in the "recommended" range...Atain, Link-->FC/CYA Levels

I would say, leave it at 40 for a few weeks and get good at keeping your FC in Range. That will give you some sense of the amount you have to run your cell, and give you practice at maintaining FC. Then add 10ppm of CYA and see how much your FC demand changes. Then you will know.

Here is my routine, I run pump 24/7: April 5%, May 10%, June 15%, July 15%, Aug 10%, Sep/Oct 0-5%. When I take the cover off, I turn the SWCG up to 50% for the duration of the cover off, and back to baseline % when the cover goes back on. My FC is stable. You can even test DURING a party and add chlorine or up SWCG %...no need to wait to the end of the day, and likely no need to run for days.

You combined "minimum" with "target". I would substitute "EVER" for crossed off words above. Never ever let it get below "MINIMUM," better, never it let it get below MINIMUM + 1. Always keep it in "Target Range."


Last thought. It is better to keep your pool at the top of the recommended range as you learn your FC demand, covered, uncovered and "party mode." That way if you are surprised by a bigger demand day than you expected, you have more "skoosh" room before you hit minimum.

all good points. thanks for taking the time to keep chiming in. I like your strategy for pump and percentage. That's similar to what I was doing before (8hrs pump and adjusting percentage based on season/demand), I (and pool service) let the chlorine go below minimum (not the low range of target) for too long. It probably wasn't much more than a week, but at 86/87 degree pool water, that is easy to breed algae I imagine. Plus we were always towards the low range of target, where being towards the top of the range probably would have prevented this whole exercise. But I actually appreciate that it happened because I have learned a lot more and have confirmed many concepts that were just "in-theory" for me.

Thanks guys! you all rock!