The Novitek Active Oxygen Tester is used to measure the pH balance and active oxygen levels of hot tub water. The kit contains a test jar, 20 phenol red tablets to measure pH, and 20 DPD tablets to measure oxygen levels.

Instructions for use:

• The tablets are placed in their own blocks in the tester, and water is drawn from the pool into the test jar.
• When dissolved, the tablets will colour the water and a visual scale on the side of the tester will indicate which pH and oxygen value corresponds to which colour.

Separately available are also tablet refill packs containing 30 tablets of Phenol red and 30 tablets of DPD.