These 1 inch compressed tabs are a way to add a sodium bicarbonate buffer to the water to book the Alkalinity. Adding 1 tab in 250 gallons will raise the total alkalinity by approx. 15 ppm. The preferred experience is to apply the tabs to the filter compartment with the pump circulating and running. Within a few minutes the tablets will fully dissolve. The tabs will still dissolve if applied to the footwell, but debris might linger in "dead spots" along the spas footwells. Note: Spa water may temporarily cloud after a start up dose or if a large correct doses are applied
