Re: mms solution for use in swimming pools

Hello Bill,

You need a concentration of free chlorine dioxide of 2 PPM.

One issue with using chlorine dioxide in pools is that it is very UV sensitive, so you have to check the concentration often and it is best to use evenings to disinfect.

Another issue is that chlorine dioxide doesn't react with ammonia. You will still need a little chlorine to take care of the ammonia build up, but if you first disinfect with chlorine dioxide the amount of chlorine needed is very small.

To get a 2 PPM free chlorine dioxide concentration in 1000 liters of water you would use 15 ml of 22.4% sodium chlorite activated with 15 ml of 27% HCl. Use caution when mixing this because at these concentrations the reaction is explosive. You would be better off diluting the 22.4% sodium chlorite in half and also doing the same with the HCl. With half the concentration of the raw chemicals you simply use twice as much.

Where 15 ml of each is needed at the higher concentrations, you would need 30 ml of each at the diluted concentrations.

If you have fish in your pool you need to reduce the concentration of free chlorine dioxide to just below 1 PPM.

If your pool is in a sunny area and receives long periods of sun, you can also add some sodium chlorite to the water to shoot for around 15 PPM available chlorine dioxide. 100 ml of 22.4% sodium chlorite in 1000 liters of water will give you a little over 13 PPM available, so that is probably close enough. When doing this you have to watch and balance the PH of the pool water. If it goes acid, it will begin activating the available chlorine dioxide and things could get a little out of hand.

Tom