Best Co2 Dauertest 2026

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Last Updated - 22.07.2026

Best Choice

01

Aqua Rebell

Aqua Rebell – CO2 Check – 20 mg per Litre

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9.8

Exceptional

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

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

17,76 €
Value for Money

02

Measury

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

25% Off

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9.7

Exceptional

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

14,95 € 19,95 €(25% Off off)
03

WALDSEELE

CO2 Continuous Test Aquarium with 15 ml Test Liquid, Colourimetric CO2 Indicator for Aquariums, CO2 Tester, Precise Glass Meter with Suction Cup for Planted Aquarium

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9.6

Exceptional

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

Protection for aquariums: continuous monitoring with the CO2 test aquarium including indicator solution promotes a stable environment, which supports plant growth and preserves the biological balance in freshwater aquariums
Precise colorimetric detection: the CO2 test aquarium monitor reliably shows the CO2 content - blue colour at too low, green at optimal and yellow at too high value for easy control
Practical suction design: the CO2 continuous test aquarium glass capacity meter with robust suction cup adheres securely to the disc and thus allows for long-term, space-saving observation without disturbing the aquarium landscape
CONTINUOUS CO2 MEASUREMENT IN AQUARIES: The CO2 continuous test aquarium with 15 ml test fluid allows precise and seamless monitoring of the CO2 concentration by simple colour observation for a healthy aquarium ecosystem
Application scenarios: the CO2 indicator for planted fish offers a reliable solution for accurately determining the CO2 content and maintaining a healthy aquarium

8,99 €
04

JBL

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

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9.5

Excellent

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

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

13,45 €
05

ARKA

ARKA mySCAPE CO2 Continuous Test Aquarium - Glass Dropchecker Including 15 ml Indicator Solution - Precise CO2 Monitoring with Colour Display for Aquascaping & Plant Aquariums

16% Off

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9.4

Excellent

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

Precise CO2 continuous test for plant aquariums - The glass Dropchecker reliably shows whether the CO2 value in the aquarium is in the optimal range. Ideal for healthy plant growth, stable water values and controlled CO2 fertilisation in the freshwater aquarium.
Includes 15 ml ready-to-use indicator solution - Simply fill, attach to the aquarium and read the CO2 status directly via the colour change. Green stands for the optimal range, blue for too little and yellow for too much CO2.
High-quality glass drop checker with suction cup - The transparent glass shape looks discreet in the basin and fits perfectly in aquascapes and planted layouts. The suction cup ensures a secure grip on the aquarium disc and a clean positioning in the viewing area.
Compatible with standard CO2 systems - The continuous test is ideal for ARKA mySCAPE-CO2, but can also be used with many other CO2 systems in the freshwater aquarium. Ideal for beginners and professionals in plant aquariums.
ARKA Quality for demanding aquascaping: Designed for easy CO2 control without technical stress and ideal for detecting deficiency or oversupply at an early stage. For aquarists who want to optimise plant growth specifically and permanently.

12,49 € 14,90 €(16% Off off)
06

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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9.3

Excellent

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

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

6,15 €
07

Editbar

Editbar Pack of 4 CO2 Glass Aquarium Monitor, Co2 Continuous Test Aquarium, CO2 Test Aquarium Drop Checker Hanging, Aquarium Co2 Monitor, Co2 Glass Tester for Freshwater Aquariums, Planted Fish Tank

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9.2

Excellent

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

【Package Includes】: You will receive 4 CO2 continuous test aquariums and 4 suction cups, including 2 hanging CO2 glass testers and 2 round CO2 glass testers. Sufficient for daily use and replacement. The streamlined and practical design allows you to easily monitor and control the water quality in the aquarium. (This product does not contain CO2 indicator fluid.)
【Multi-purpose】The aquarium CO2 tester is suitable for all kinds of aquariums, especially plant aquariums and tropical aquariums. It helps you monitor the CO2 content in the water and keep your fish and plants healthy.
【High Quality Materials】:This CO2 test aquarium dropper is made of high quality glass, crystal clear, durable and corrosion resistant. It is easy to observe and clean. Users can intuitively observe the colour change of the CO2 indicator in the detector.
【Easy measurement】: Simply fill the CO2 indicator into the CO2 glass instrument and attach it to the inner wall of the aquarium with the suction cup. The CO2 indicator solution glows blue for low CO2 content, green for optimal CO2 content and yellow for excessive CO2 content. Please change the liquid every three weeks to ensure accurate and reliable results.
【Adsorption Design】This CO2 glass tester is specially designed for aquariums. Equipped with a strong suction cup, it sticks firmly to the inner wall of the aquarium, does not take up space in the aquarium and does not hinder the fish in their movement.

9,99 €
08

ARKA

ARKA mySCAPE CO2 Indicator Solution Aquarium 15 ml - Test Liquid for CO2 Continuous Test & Dropchecker - with Colour Change for Precise CO2 Control in the Plant Aquarium

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9.0

Excellent

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

Universally suitable for standard CO2 testers - The liquid is ideal for the ARKA mySCAPE-CO2 checker and can also be used with many standard CO2 continuous tests in the freshwater aquarium. Perfect for flexible use in different setups.
Reliable CO2 test liquid for permanent testers - The ARKA mySCAPE-CO2 Checker Liquid has been developed for precise monitoring of the CO2 supply in the freshwater aquarium. Ideal for aquascaping, plant aquariums and permanently controlled CO2 fertilisation.
Clear colour impact for quick reading - The indicator solution shows the CO2 status in the aquarium via three colours. Yellow stands for too high, green for optimal and blue for too low. For quick control without calculating or additional tables.
ARKA Quality for precise CO2 control - Developed for aquarists who want to specifically control plant growth and keep an eye on CO2 values. Ideal for permanently stable water values and healthy plant growth in aquascape.
15 ml ready-to-use test liquid - The solution is ready to use and can be easily filled into a matching CO2 continuous test or Dropchecker. Ideal for regular refill and continuous CO2 monitoring in the tank.

5,89 €
09

Generisch

Yerleomit CO2 Continuous Test Aquarium CO2 Diffuser Aquarium CO2 Test Aquarium Tester Aquarium Airstone CO2 Monitor Disc Capacity Meter Aquarium with Suction Cup for Planted Aquarium

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8.9

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

CO2 continuous test aquarium with high-quality material: this round CO2 permanent test aquarium 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.
CO2 continuous test aquarium with adsorption design: this round CO2 permanent test aquarium 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.
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

6,35 €
10

Measury

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

25% Off

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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.

Show more
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).

14,95 € 19,95 €(25% Off off)