if you want to test, do so after the eco3spa Sanitiser tablet(s)/granules are completely dissolved. The ideal Active Oxygen level is shown on the graduated colour scale on the side of the test strip container. Simply dip a strip into the spa water and compare with the colour chart shown as 'OK' on the container's label. If no level is shown then add a sanitiser tablet/spoonful of granules and test again when the sanitiser is fully dissolved and circulated. These strips test for Active Oxygen only. There is no need to test for pH or Alkalinity as eco3spa works independently of these factors.
