[tomtailford]

Hello,

Have a 90,000L swimming pool with 1.7ppm Sodium hypochlorite.

It's an external salt-water pool and I wondered how long it would take to drop below 0.5ppm sodium hypochlorite just being exposed to sunlight.

Is there a simple calculation for this or not really?

Also, can people suggest ways in which we could speed up the degradation (which are not heating!)... it's already exposed to sunlight.

Could maybe add Sodium metabisulphate or something similar?

Thanks for any help,

Tom

[hobobot]

sodium metabisulphite works great.  I think the end products are NaCl and Na₂SO₄.

[Dietitian]

Hello,

Have a 90,000L swimming pool with 1.7ppm Sodium hypochlorite.

It's an external salt-water pool and I wondered how long it would take to drop below 0.5ppm sodium hypochlorite just being exposed to sunlight.

Is there a simple calculation for this or not really?

Also, can people suggest ways in which we could speed up the degradation (which are not heating!)... it's already exposed to sunlight.

Could maybe add Sodium metabisulphate or something similar?

Thanks for any help,

Tom

You can use hydrogen peroxide to reduce it to 0.5 ppm, but 1.7ppm is not dangerous and you can swim at that level.  About 100 oz of H202 should do the trick for 90k gallons.