Yes. A little essay I wrote a couple years ago explains it.
Originally Posted by mackguy
We'll take a 16000 gallon pool, because that's what I have. On a fresh fill, prominent national pool chain recommends 2.5 pounds pf stabilizer per 10,000 gallons, which works out nicely to 4 pounds which brings CYA to 30.
With an average loss of 2 PPM/Day or 14 ppm/week, I'll have added 8.6 PPM/CYA if I used trichlor pucks perfectly. And they recommend a weekly "shock" of dichlor between 5 and 10 FC.... 2-3 oz per 10,000 gallons. Split the difference; I'll add 4 oz. CYA went up another .9.
So..by the end of week one, I have added 9.5 more CYA. It is now 39.5. Mimimum FC for that is 3, so I'm probably okay.
Week two, up to 49 CYA.
Week three, 58.5. Minimum FC should be 5, but they recommend 3 as ideal, so the pool looks a bit hazy. So I'll toss in a little extra dichlor "shock" to jack FC up to 10. Which adds another 6.4 CYA. Keeping count? We're up to 64.9 now.
That caught the algae just in time.. we had two weeks of good luck. A steady diet of pucks and 4 oz. "shock" each week only added another 19, up to 73.9 now.
Week 6 it started looking funky, so we "shocked"it once again. CYA is up to 99.3. But minimum FC to keep algae at bay is 8, and we're still holding things to 3, because prominent national chain's preprinted sheet shows that as ideal. So algae got a toehold and the pool has a bit of a tint. So we throw two whole bags of dichlor in which jacks it another 7.6 by the time week 7 is over, we're at 116.4, because we had pucks in the floater the whole time.
So...in 7 weeks, from 30 to 116.4. Let's say there are no more algae outbreaks because they sold me a huge bucket of phos-free and another of yellow-out monopersulfate "shock" Nothing but the pucks and the extra 4 oz of dichlor "shock" weekly. So the next 7 weeks added 66.5, which brings the total to 182.9 CYA.
Now if we didn't understand this and things looked a bit hazy, we might throw an extra puck or two in the floater every couple weeks, which will drive it over 200 easily.
Would you buy a car with a gas gauge that said you were somewhere between empty and half a tank?
I understand the test strips are not 100% accurate but are they really that far off, in that they show I'm between 0-50 "stabilizer"?
If you believe the hardness reading, it means too much Calcium. But with all the snake oils you've been adding and the inherent errors in pool store testing and test strips, I wouldn't trust the readings or get excited yet. If your tests show it that high, you're at serious risk of Calcium scale. Sort of grow-your-own sandpaper. Good way to exfoliate, just brush against it. Or get horsing around and get pushed into the wall and end up with roadrash. If you're in a naturally hard water area, it is easy to get way high on hardness. If you start dumping buckets of Calcium Hypochlorite "shock" in there, that raises it too.
Also, does the 1,000+ hardness indicate anything troubling? My pool guy also had me run "metal magic" and I also ran polyquat algaecide.
Wish I'd found this site before spending ~$500 on pool chemicals for the year!
$500 would keep my pool going for almost two full years, including test kit refills. Not including electricity for the pump, though. But that would be the same whether the pool was crystal clear or foggy. That free testing sure saves a bunch!