too much chlorine

[flyfisher]

The automatic chlorine feeder for my indoor pool was miscalibrated. I now have 8+ ppm of cl. After a shock treatment, it typically takes a week or more for cl. levels to drop to the point that we can use the pool. Sodium thiosulfate will neutralize the chlorine, but I can find no formula to let me know how much thio. to use. Can anyone help me?

[dynamictiger]

Hi

0.5 kg per 100,000 litres destroys 1 mg/l.

HTH

[pooluser]

Hi

0.5 kg per 100,000 litres destroys 1 mg/l.

HTH

I read here 102 grams for 1 ppm / 100 000 liters using thiosulfate pentahydrate 100%. I guess your mileage may vary.

Also you may wish to buy thiosulfate from a camera supply store as opposed to a pool store, much less expensive.

[dynamictiger]

That is one of the problems with thiosulphate the reaction is dependant on outside factors, such as pH and cyanuric as well as some unknown factors.