To raise your pH or alkalinity first turn off all the jets.
If your pH is reading between 6.8 and 7.2 add just one ounce of HT pH alkalinity Up. If your pH reads below 6.8 then the amount changes to two ounces. In swim spas with up to 1,000 gallons double these amounts.
For best results you should premix the product in a small bucket of spa water and pour it back in as close to the center of the spa as possible.
Then turn on your filtration pump and wait 3 hours and retest the water. If it is still low repeat the procedure.