Best Co2 Dauertest 2025

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Last Updated - 26.07.2025

Best Choice

01

noble aqua

noble aqua CO2 Continuous Test Aquarium 150 ml CO2 Indicator Liquid 20 mg/l CO2 Test Meter

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9.9

Exceptional

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Simple and durable CO2 measurement – attach the continuous test in the aquarium and read CO2 content at any time on the colour of the test liquid
Precise measurements - CO2 test fluid from Germany - colour change to green at 20 mg/l CO2 - optimal CO2 content for plants and animals
Magnificent plants and healthy fish - allows the exact adjustment of the CO2 system for a perfectly fertilised aquarium - suitable for all organic and compressed gas CO2 systems
Attractive glass test - made of high-quality borosilicate glass - fits perfectly into any aquarium
150 ml test liquid - for many fillings without frequent reordering

22,90 €
02

Aqua Rebell

Aqua Rebell – CO2 Check – 20 mg per Litre

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9.7

Exceptional

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Perfect for optimal CO2 content in an aquascape
Easy to read due to colour change at different pH values

21,85 €
Value for Money

03

Yerleomit

Yerleomit CO2 Continuous Test Aquarium Drop Checker Test Aquarium CO2 Monitor Aquarium Glass Capacity Meter Aquarium with Suction Cup for Planted Aquarium

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35% Off
9.6

Exceptional

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CO2 continuous test aquarium with strong suction cup: the CO2 permanent test aquarium with strong suction cup, simply attach to the wall of your aquarium and does not fall off easily.
CO2 continuous test aquarium material: the CO2 continuous test aquarium made of high-quality glass, for measuring the CO2 content at a glance.
CO2 continuous test aquarium indicator colour shows results: the CO2 permanent test aquarium indicator solution is blue, if it is blue, this means that CO2 is insufficient; turns green, the CO2 balance; turns yellow, means that your tank contains too much CO2. Make the necessary adjustments and test until you turn green.
CO2 continuous test aquarium application: the CO2 permanent test aquarium is used to test and monitor the concentrate of the aquarium water plant aquarium and is suitable for aquariums, aquariums, especially water plants, tropical fish for observing and cultivating aquariums.
Box contents: 1 x CO2 continuous test aquarium (no including indicator solution), 1 x suction cups

3,30 € 5,15 €(35% Off off)
04

JBL

JBL ProAquaTest CO2-pH Permanent ProScan Recharge with 24 Water Analysis Strips.

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9.5

Excellent

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Main highlights

For direct use thanks to the complete set with display container with suction cup, reagents and colour scale stickers, refill reagent available separately for refilling
Displays pH value from 6.4 to 7.8 and CO2 content
Continuous test for fertiliser control: place reagent in permanent test device and attach to the disc in the aquarium with teats, compare the reagent colour with colour scale sticker and read the value
Box contents: 1x JBL water test set, ProAquaTest CO2-pH permanent, includes 1 display container with suction cup, 2 reagents and colour scale sticker
Advanced water test series: simple and safe control of the water values of freshwater aquariums, ideal for permanent direct measurement of the optimal pH value and carbon dioxide content

14,49 €
05

ARKA

ARKA mySCAPE-CO2 Checker - Includes 15 ml Indicator Solution - CO2 Continuous Test with Colour Display for Precise Monitoring in Freshwater Aquariums, Essential for Aquascaping

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16% Off
9.2

Excellent

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Main highlights

Universal: ideal for use with many standard CO2 supply systems, such as the ARKA mySCAPE-CO2 system.
Easy to place: the CO2 test glass container can be easily attached to the aquarium disc by means of a suction cup from the inside.
Colour display: the control fluid, which is filled into the glass container acting as an aquarium CO2 test, has a colour change, which shows the status of the CO2 supply in the aquarium at any time and can therefore be used as a reliable aquarium CO2 continuous test.
ARKA mySCAPE CO2 CHECKER SET: A CO2 tester made of glass and 15 ml CO2 indicator liquid, ideal for permanent and easy monitoring of the CO2 supply in any freshwater aquarium.
ARKA Biotechnologie GmbH has been developing and producing high-quality products for aquariums, pond care, DIY supplies as well as accessories for dogs, cats and rodents for years – known for innovation and quality – made in Germany

12,49 € 14,90 €(16% Off off)
06

Begpoee

Begpoee Pack of 2 CO2 Glass Aquarium Monitor, CO2 Tester Aquarium, Aquarium CO2 Monitor, CO2 Glass Tester, CO2 Test Aquarium Drop Checker, CO2 Tester, for Freshwater Aquariums Planted Fish Tank

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9.0

Excellent

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Product contents: 2 x round aquarium carbon dioxide instrument and 2 x suction cups (this product does not contain a CO2 indicator). This set is a must have for the aquarium. It features a beautiful and practical design that allows users to easily monitor and manage the water quality of the aquarium, providing a practical and reliable tool for maintaining the ecological environment of fish.
High-quality material: This round CO2 instrument for aquariums is made of high-quality glass material, which is durable and corrosion resistant. It resists chemicals and moisture in the water, ensuring a long service life. The round CO2 instrument has high transparency and users can visually observe the colour change of the CO2 indicator inside the detector.
Easy to use: simply pour the CO2 indicator into the round CO2 instrument, then install the suction cup and then stick the instrument to the inner wall of the aquarium via the suction cup. The colour of the CO2 indicator is blue. At low CO2 concentration, the colour appears green. If the colour gradually changes to yellow, it means that the CO2 concentration gradually increases.
Application: This CO2 round instrument is suitable for different types of aquariums. Whether it is a freshwater aquarium, a saltwater aquarium or a plant breeding aquarium, it can help people maintain the balance of CO2 content in the aquarium and determine whether the water quality is suitable health and reproduction of living beings.
Adsorption design: This round CO2 instrument has been specially developed for aquariums. It is equipped with a strong suction cup that can be firmly adsorbed to the inner wall of the aquarium without taking up the space of the aquarium or affecting the activities of the fish. The adsorption design makes the installation process easy and fast without the need to use tools or perform complicated operations.

7,99 €
07

CENPEK

CENPEK CO2 Drop Checker Glass Aquarium Monitor CO2 Indicator for Planted Fish

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11% Off
8.8

Very Good

Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

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Main highlights

You need to be very careful with the health of your plants and carbon dioxide is one of their main requirements.
This CO2 monitor is one of the most important items of your aquarium kit that helps you to constantly control the CO2 content in the water.
The monitor should be installed about 10 cm below the water surface. It is recommended not to install too far from the refiner.
Suitable for aquariums, aquariums, especially aquatic plants, tropical fish to observe and cultivate aquariums.
CO2 drop tester made of high quality glass, for measuring CO2 content at a glance (without indicator solution).

7,99 € 8,99 €(11% Off off)
08

Measury

Measury CO2 Continuous “Orb” Test for Aquariums - Made in Germany - 30 ml Test Fluid 20 mg/l - CO2 Test Drop Checker - CO2 Tester

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8.7

Very Good

Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

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Main highlights

Test liquid made in Germany: As the CO2 content in aquariums is crucial to the health of its inhabitants, we have not compromised at all. Our 30 ml CO2 test liquid is produced in Germany in an ISO-certified production facility
Super-strong suction cup: the test orb holds firmly on the glass thanks to its extra-strong suction cup
High-quality borosilicate glass: clear, perfectly shaped borosilicate glass, as used in laboratory equipment, makes the test orb a real eye-catcher
CO2 measurement in aquariums: Determine the CO2 level in your aquarium by observing a change of colour in the test fluid, which is filled in the continuous test. If the CO2 content in the aquarium is 20 mg/l, the solution turns green
Box contents: 1 x CO2 continuous test glassware, 1 x 30 ml indicator liquid 20 mg/l, 1 x suction cup and 1 x instructions in German (English language not guaranteed).

19,95 €
09

Heveer

Co2 Continuous Test Aquarium 2 Pieces Aquarium CO2 Monitor CO2 Test Drop Checker Aquarium Co2 Tester for Aquarium Freshwater Aquarium Fish Tank

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8.4

Good

Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

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Main highlights

STRONG SUCTION CUP DESIGN The strong suction cup design easily attaches to the side wall of the aquarium, ensuring that the long-term tester stays firmly in place.
MULTIPURPOSE Ideal for various aquariums, especially plant tanks and tropical fish tanks, and helps monitor and adapt the growing environment of aquatic plants and fish.
HIGH QUALITY GLASS CONSTRUCTION This tester made of durable glass is crystal clear and tough to measure CO2 levels at a glance. Also with a unique round design that increases its aesthetic appeal.
Easy to observe: the CO2 indicator shows blue for low CO2, green for optimal CO2 content and yellow for excess CO2, which makes monitoring easier.
Accurate CO2 detection: essential for any aquarium. Measures CO2 levels by observing colour changes in the long-term test fluid (CO2 indicator not included).

7,69 €
10

Measury

Measury CO2 Continuous Test Aquarium, Made in Germany, 30 ml Test Fluid 20 mg/l, CO2 Test Drop Checker, CO2 Tester

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8.3

Good

Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.

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Main highlights

Test liquid made in Germany: Since the CO2 content in the aquarium is crucial to the health of its inhabitants, we have not made any compromises. Our 30 ml CO2 test liquid is produced in Germany in an ISO certified production facility.
Super strong suction cup: Thanks to the extra strong suction cup, the permanent test holds firmly on the window.
High quality borosilicate glass: Clear, perfectly shaped borosilicate glass, as used in laboratory equipment, makes the long-term test a real eye-catcher.
Delivery contents: 1 x CO2 continuous test glassware, 1 x 30 ml indicator liquid 20 mg/l, 1 x suction cup, 1 x instructions in German
CO2 measurement in the aquarium: By a change of colour of the test fluid, which is filled into the continuous test, the CO2 content in the aquarium can be determined. If the CO2 content in the aquarium is 20 mg/l, the solution turns green

19,95 €