Chlorine Generator Spa Startup, Not Making Enough Chlorine

Spa startup with a saltwater chlorine generator the water is usually replaced to start with fresh water and then salt is added. For a salt concentration of 2000 PPM that is about 1.5 pounds per 100 gallons of water. Then the water should be balanced which entails at a minimum bringing the pH to 7.5 and the chlorine to 2 PPM.

If the water isn’t balanced with chlorine then a typical problem is the chlorine generator can’t break from a 0 chlorine reading even after a couple days. This type of problem typically only happens at start-up because the fresh water typically has more organic material content and can be high in phosphates leading to a higher chlorine demand than a hot tub chlorine generator can produce. Once the organic material is removed and the phosphates are lowered the chlorine demand of the hot tub water will be reduced and the chlorinator can now make chlorine faster than the spa is consuming it.

Even the salt contributes to the chlorine demand as the salt will most likely have a powdery coating on it unless it was rinsed first. The water should be balanced after the salt has dissolved to also remove any organic material introduced by the salt.

When the water is replaced and after the salt has been added the water should be shocked and a suitable phosphate remover used. If the hot tub chlorine generator will not be on for a couple days then a chlorine based shock should be used. If the chlorinator will be used during start-up a chlorine free shock can be used. When adding phosphate remover simply add a cap-full and if the water gets a white tint to it like a white fog there are phosphate so then add the recommended amount of phosphate remover per the directions on the bottle. After the filter has cleared up the water repeat the process until the water doesn’t turn white when adding the phosphate remover.

4 Comments

  • Ted Decker

    Reply Reply April 18, 2016

    Looking for an option to register my recently purchased Chlormaker. I can’t find it on this site. I have a Chlormaker DO with a concealed install kit Purchased from Hot tub covers Canada. The serial number is 631621.

    • admin

      Reply Reply April 27, 2016

      Hi Ted and thanks for pointing out the difficulty in finding our registration. Go to http://www.controlomatic.com/support/ and product registration is in the middle. We have been updating our site and it does look like if you find this page it is easy, but we will get it added to the footer on all the pages.

  • Korey Oskins

    Reply Reply April 26, 2018

    Hello,
    Do I need to test for phosphates first? Or assume the water contains them if I’m not getting a chlorine reading? My spa is testing high on PH and alkalinity. Water hardness is also high, but maybe that’s the salt minerals? I am using a spa down product and it has only lowered incrementally. Is there something I’m doing wrong? Should I shock it and try again?

    • admin

      Reply Reply July 10, 2018

      The cost of a phosphate test kit is about the same as phosphate remover so just get the remover. When you put it in the water will turn foggy if there are phosphates so let the pump run a couple hours and then clean the filter.

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