Orp vs. high chlorine

[bobobi-wan]

what is the best way to lower the chlorine in a pool that has a controller that measures orp.previous methods included lower orp set point (not reccomended by controller people)and raising orp with mps and riding it out.chlor-out lowers orp as it lowers chlorine.

[Me...]

A bit confusing there. ORP is a value commonly accepted as being a measure of the chlorine level in the water. In fact some PPM controllers actually only measure ORP and use math to convert and display a PPM value.

If your ORP controller is putting too much chlorine in the water and the controller is properly calibrated, then you simply lower the ORP setpoint. That is exactly the right thing to do. If the ORP reading seems to spike to very high readings and then eventually settles back down then you need to

1. decrease on time. or

2. increase off time. or

3. dilute the solution. or

4. Slow down the feed rate.

If you use anything to lower the chlorine reading such as Sodium Thiosulphate you need to make sure your probes are isolated until the water settles. That stuff hitting the probes will most likely destroy their ability to read properly.

[bobobi-wan]

I have reduced feed rate,put in #3 stenner tubes(from #5)and I wondered about diluting the chlorine(I have 30 gal.barrels).The Shasta rep says that heat we have in Az. might affect the need for a 650 orp min. and he suggested lowering the orp to whatever will keep the pool at 1.5 to 2.0. I was using thiosulfate almost daily,about 3 oz.,or letting the sun burn off the excess.

[Me...]

What controller?

[bobobi-wan]

Poolcomm Cat 4000.and I just had another flow switch go down,they need to improve their sensors.