New pool, trichlor tabs for the past 17 years, Where do I go from there?

[dmeyer]

UPDATE: I dilluted a sample down to 1/4th and arrived at just under 240ppm CYA.

For what it's worth, I also found some old water analysis done by a national chain. They found that CYA was 121 this time last year, and in 2010 it was 161.

Finally, I no longer believe the 30k gallon number (which is from that same shop) is accurate. I think the real number is in the 20-25K gallon range, probably closer to 20K gallons.

[PoolDoc]

Order a K2006 (Amazon link in my signature) if you don't have one (not sure what a "Taylor 2600", above, is), then read the Best Guess page, linked in my signature.

Using the CYA test from the Taylor 2006, do a careful test on a mix of 3/4 cup tap water + 1/4 cup pool water for CYA to establish your actual CYA level (= 4x test result level!)

Begin operating with chlorine levels from the Best Guess chart -- for CYA = 150, probably you want to dose to near 20 ppm FC, and let the pool 'coast' till it reaches 10 ppm. Brush on days when chlorine is high.

Read the polyquat page, and stockpile 2 quarts of polyquat per 10K gallons of pool water. It's currently about $17 @ Amazon, with free shipping and no tax in many states. Begin using polyquat at first sign of algae, rather than 'shocking' to levels of 30+ ppm.

Otherwise, swim and enjoy. 20 ppm FC is *not* a problem when CYA = 150 ppm, though you might not want to wear brand new expensive fashion swim suits in it. Skin is far, far more chlorine resistant than fashion Lycra.

Ironically, operating this way may be both EASIER and CHEAPER than doing a more normal operation. You'll probably be able to dose with bleach or cal hypo just 1x per week!

If you use cal hypo, keep an eye on your calcium levels and pH.

When testing pH, take your readings within 10 seconds of adding phenol red. When FC > 10 ppm, use ONLY the Taylor reagents. The high chlorine will invalidate your pH readings, if you let the sample sit before reading.

Good luck!

[dmeyer]

Order a K2006 (Amazon link in my signature) if you don't have one (not sure what a "Taylor 2600", above, is), then read the Best Guess page, linked in my signature.

Using the CYA test from the Taylor 2006, do a careful test on a mix of 3/4 cup tap water + 1/4 cup pool water for CYA to establish your actual CYA level (= 4x test result level!)

I'm using the K2006, and I used the method you describe above to estimate a CYA level of 240.

Begin operating with chlorine levels from the Best Guess chart -- for CYA = 150, probably you want to dose to near 20 ppm FC, and let the pool 'coast' till it reaches 10 ppm. Brush on days when chlorine is high.

At a CYA over 200, It seems I'm off the chart, but I suppose I should still be cruising around 10-20ppm of chlorine? The chart is a bit wide open at the high end.

Read the polyquat page, and stockpile 2 quarts of polyquat per 10K gallons of pool water. It's currently about $17 @ Amazon, with free shipping and no tax in many states. Begin using polyquat at first sign of chlorine, rather than 'shocking' to levels of 30+ ppm.

Will do! I think you mean for me to use polyquat at the first sign of algea?

Otherwise, swim and enjoy. 20 ppm FC is *not* a problem when CYA = 150 ppm, though you might not want to wear brand new expensive fashion swim suits in it. Skin is far, far more chlorine resistant than fashion Lycra.

Ironically, operating this way may be both EASIER and CHEAPER than doing a more normal operation. You'll probably be able to dose with bleach or cal hypo just 1x per week!

If you use cal hypo, keep an eye on your calcium levels and pH.

When testing pH, take your readings within 10 seconds of adding phenol red. When FC > 10 ppm, use ONLY the Taylor reagents. The high chlorine will invalidate your pH readings, if you let the sample sit before reading.

Good luck!

Gotcha. Sounds like a plan.

[Watermom]

He did mean "at the first sign of algae." I had already caught that and fixed it in his post above.