Aqua Rebell CO2 Check 250 ml

Aqua Rebell CO2 Check 250 ml

  • Safe determination of the CO2 content
  • No need to mix with aquarium water
  • Can be used in all drop checkers
  • Easy to read
  • Perfect for optimising the CO2 content of an aquascape
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The Aqua Rebell CO2 Permanent Test Solution "CO2 Check - 20 mg per litre" or "30 mg per litre" can be filled into any standard CO2 permanent test and serves for the long-term monitoring of the CO2 level in aquariums. An optimal CO2-supply is essential for the thriving of aquatic plants and should therefore be continuously monitored. The advantage of the CO2 Permanent Test Solution is that the determination of the CO2-supply takes place independently of the aquarium water, thus substances such as humic acids cannot affect the CO2 check.

Available in a 250 ml container.

A pipette for filling the permanent test is included in the delivery.


The permanent test is filled with 1 - 2 ml of the CO2 Permanent Test Solution and then positioned in a well-circulated area in the aquarium. After about 1 - 2 hours, the CO2 content of the aquarium water can be read. A green colour indicates an optimal CO2-supply of approximately 20 mg/l or 30 mg/l.

A CO2 permanent test is very useful in an aquarium. Often, aquatic plants lack the essential CO2, preventing optimal growth. With a CO2 permanent test, the CO2 level can be controlled with sufficient accuracy. The dye bromothymol blue used has the property of changing colour in a defined pH range.

CO2 diffuses from the aquarium water through the air bubble in the permanent test into the test solution and vice versa. Depending on its CO2 content, the pH value of the test liquid and thus its colour changes. A defined carbonate hardness in the test liquid determines at which CO2 concentration a certain pH value is established. The test solutions "CO2 Check 20 mg per litre" and "30 mg per litre" turn light green when their pH value is around 6,6. This is achieved at a CO2 concentration of 20 mg/l or 30 mg/l. For this reason, the test solution "CO2 Check 20 mg per litre" or "30 mg per litre" indicates a light green tone at a CO2 value of the aquarium water of 20 mg/l or 30 mg/l. If the CO2-supply in the aquarium is less than 20 or 30 mg per litre, the test reagent remains blue; if the CO2-supply exceeds the mark of 20 or 30 mg per litre, the test reagent turns yellow.

Aqua Rebell

Aqua Rebell

Aqua Rebell is our own aquatic plant fertiliser label. A great number of planted tank enthusiasts in general and aquascapers in particular use our products to supply their aquarium plants with nutrients.

When developing fertilisers and other aquascaping-related products, we work hand in hand with a base of aquarium enthusiasts and aquascapers, and we try to realise as many of their desires and ideas as possible. Quite often, ideas and wishes uttered in our aquatic plant lovers' and aquascapers' community are the basis, on which we develop new products. These are then thoroughly tested by experienced aquarium keepers and aquascapers. Behind our product range, there are a lot of innovative ideas and long-term experience, and they are tested in real life. For us it is important that aquarium keepers and aquascapers are successful with our products and that they are thus enabled to make the utmost of their tanks and aquascapes.

General information

Item no.
EAN 4250585205680
Weight 0,29 kg
Shipping weight 0,30 kg

Customers ask customers

You have questions about this product? Ask other customer or our support team about this product!

How long can I store this product in the bottle when it is opened?
Daan V.
May. 2023
Aquasabi Support
Jun. 2023
If the CO2 check is stored in a cool and dark place, it can be kept for at least 2 years.

Customer reviews

This item has been rated 4.9 out of 5 stars
169 Reviews
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5 Stars(151)
4 Stars(12)
3 Stars(6)
2 Stars(0)
1 Star(0)
Francisco G.
9th February 2021
Aqua Rebell - CO2 Check - 30 mg/l - 250 ml
Aqua Rebell - CO2 Check - 30 mg/l - 250 ml

Óptimo produto, fácil de utilizar, fiquei fã, vou continuar a utilizar sempre nos meus aquários com co2 de certeza. Muito bom

Michael B.
Alot of fluid
23rd March 2018
Aqua Rebell - CO2 Check - 20 mg/l - 250 ml
Aqua Rebell - CO2 Check - 20 mg/l - 250 ml

There's nothing much to say about this more then its alot of bang for the buck. im happy to have this solution.

Joel C.
21st December 2016
Aqua Rebell - CO2 Check - 30 mg/l - 250 ml
Aqua Rebell - CO2 Check - 30 mg/l - 250 ml

Very useful, because the tank water must never be used in drop checker. With one bottle you can fill your drop checker for years. (read more)

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