JBL CO2-pH Permanent Test 2

Brand: JBL

JBL CO2-pH Permanent Test 2 is backordered. We will ship it separately in 3 to 7 days.



  • Simple and reliable monitoring of the water values in aquariums. Permanent direct measurement of the optimal pH value and carbon dioxide content for freshwater aquariums.
  • Permanent test to monitor fertilisation: add reagent to permanent test device and attach with suction cups to the aquarium pane. Compare reagent colour with colour scale label and read value
  • Indication of pH value (6.4 – 7.8) and CO2 content
  • Online Laboratory: regular control for a healthy aquarium with natural conditions. JBL has water tests in the form of quick tests or colour change tests for every water analysis. Testing aquarium water for healthy, clear water
  • Package content: 1 permanent test, Test-Set CO2 Permanent incl. permanent test, 2 reagents and adhesive colour chart. Refill reagent and indicators available separately


How do I properly open/close the CO2/pH permanent test diffuser?

To open the CO2/pH permanent test diffuser (angled model with black stand) just pull at the transparent cover with a sharp tug. The lid fits very tightly to prevent the diffuser liquid from leaking into the aquarium. To easily close the CO2/pH permanent test 2 diffuser (round model with white back) we recommend lubricating the seals with JBL SiliconeSpray. It is advisable to attach the lid in a tilted position and to press firmly against the bottom for 3-5 seconds to make sure that the rubber seal slips inside. Otherwise you can repeatedly press in “pumping strokes”. This ensures that the seal does not slip off and the diffuser liquid does not escape into the aquarium. 

Both instructions apply to all batches manufactured until 10/2016. Subsequent models are provided with a modification which reduces the described effect if problems occur

Despite CO2 fertilisation the indicator remains blue

No CO2 is generated when fertilising with so-called liquid carbon. Therefore the test is not able to indicate CO2, which means that the indicator always remains blue! If you add CO2 in gas form you need to increase the amount or the duration.

JBL COâ‚‚/pH-Permanent: Does ozone affect or distort the measuring of the CO2 permanent test?

Depending of the dosage it is quite possible that the ozone attacks the indicator of the CO2 permanent test and “oxidizes”. A reasonable continuous measurement of CO2 is then not possible with this method.

Is the fluid of the JBL COâ‚‚/pH-Permanent Test harmful to the tank inhabitants if some of it gets into the water ?

The fluid itself with the colour indicator is not harmful in any way with the high dilution in the tank and, in addition, it decomposes very quickly.

Do my water tests still work although they have been open for nine months?

Basically a sealed test keeps longer than an open one. How much the shelf life is reduced depends crucially on the handling and the storage conditions of the reagents. It may happen that a reagent in a test that has been open for 9 months doesn’t indicate correctly any more. However, additional information is needed to answer this question properly.

The reagent in the JBL COâ‚‚/pH Permanent Test decolourises after a few days.

It is very likely that a bacterial biofilm has formed in the container. Please place the reaction vessel in hot water (> 40 °C) for approx. 10 minutes. In order to do so, it must be taken apart and then put together again afterwards. Please do not use boiling water, as this may cause damage to the plastic.

Is the drop count of 35 correct for JBL Test-Set COâ‚‚/pH-Permanent ?

Yes, the drop count is correct. This is the reason why two bottles of indicator solution are included with the test. With the new JBL Test-Set COâ‚‚/pH-Permanent the indicator solution is no longer prepared in the aquarium water. The indicator is adjusted to a fixed carbonate hardness so that incorrect measurements (as when humic acids enter the aquarium water) no longer occur.

What is the shelf life of the JBL COâ‚‚ Permanent Test ?

The JBL COâ‚‚ permanent test has a shelf life of 3 years in the original sealed bottle. 

The following is printed on the bottom of the packaging: 

CH/B: 2413 (e.g.) = batch number BBD: 09/13 (e.g.) = best-before date (month/year) 

Please note that the best-before date does not apply for opened reagents. Exposure to atmospheric oxygen decreases the shelf life.

Aren’t these two statements about the JBL CO2/pH-Permanent test contradictory ? The special indicator shows the CO2 level independently from substances in the water, such as humic acids or nitrate, which influence the pH value. The pH permanent test only works when no substances, such as pH-Minus or peat, which influence the pH values, are added.

No, the two statements do not contradict each other. 

The indicator reacts to the pH value of the test liquid. The indicator in the JBL CO2/pH-Permanent test only changes colour because of the carbon dioxide which has diffused from the water into the test liquid. 

Humic acids or other acids have a pH-reducing effect. As a result the real pH value in the aquarium water can be lower than that shown in the indicator, which is only influenced by the diffused carbon dioxide inside the water.