The JBL Permanent Test CO2 plus pH is a beautifully designed unit for attaching inside the aquarium which permanently displays the pH value or the CO2 content of the aquarium water. Two separate colour scales, one for pH and the other for CO2, are included with the unit to be attached to the pane of the aquarium, as required.

• Comparison of staining of liquid against a colour-scale adhesive label enables both the CO2 content and the pH to be read at all times.
• IMPORTANT: Also includes the carbonate hardness.
• Accurate reading through white background in the test container.