Aquarium CO2 Drop Checker Solution 15ml


Regular price $7.99

Aquarium CO2 Drop Checker Solution 15ml. 

It consists of a pre-made 4dKH solution containing the appropriate amount of reagent. No mixing nor preparation is needed for its easy use. Simply open the bottle and fill the CO2 drop checker.

  1. Fill the drop checker 2/3 full of CO2 Drop Checker Solution (about 25/30drops)
  2. Now invert it, being careful not to spill the fluid 
  3. Next, holding it level, mount the checker anywhere on the front glass inside the tank so that air is trapped in the vessel
  4. When the reagent solution is deep green, the optimum amount of CO2 is diluted in the water column
  5. Replace CO2 Drop Checker Solution minimum once a month to maintain an accurate read.

When the drop checker is submerged in the aquarium, the carbon dioxide in the water will fill the airspace of the drop checker and will eventually be absorbed into the indicator solution. The carbon dioxide will seek a point of equilibrium between the indicator solution and the aquarium water. As equilibrium is achieved, the color of the indicator solution inside of the drop checker will change based on the concentration of CO2 in the water column.

If the indicator solution is deep green in color, then appropriate levels of carbon dioxide are present in the aquarium and no action is required. If the solution changes to blue or yellow, then the CO2 levels are too low or too high, respectively. When the reagent turns yellowish, your livestock can be in danger as too much CO2 is lethal to fish. 

Drop Checker Kit installation tutorial:



Warranty 10 Years 5 Years
Construction Dual Stage Dual Stage
Integrated 12VDC Solenoid Valve
Maximum Working Pressure 80PSI / 5.5Bar 40PSI / 2.7Bar
Pressure Stabilisation ~ 1PSI ~ 5PSI
Bubble Counter with integrated check valve
Inline Atomizer Compatible
In-Tank Bazooka Atomizers Compatible
Standard Ceramic Diffuser Compatible
Low-pressure Reactor Compatible
End Of Tank Dump (EOTD) Prevention
Adjustable Working Pressure
CGA320 Connection Option
Stackable Outlets X
Multi-Diffuser compatibility X
CO2Art delivers products with outstanding quality. And great products come with great service.
That is why we can offer up to ’10 Year Warranty’!


The following product receives a 10-year warranty:
The following product receives a 5-year warranty:

All other products receive the standard 2-year manufacturer’s warranty 

*Please note that the warranty that CO2Art offers is non-transferrable

In addition to our industry-leading warranties, all CO2Art customers receive lifetime:


Scope of Warranty
This warranty covers any defects in materials and workmanship under normal home use.
Period of Coverage
This warranty runs for a minimum of two years from the date of purchase. Please save your receipt.
Failures due to abuse or misuse are not covered by this warranty. Surface coating problems caused by excessive humidity, in-use scratches or abrasions, and direct exposures to the elements are also not covered.
Repair or replacement is the only option available under this warranty. CO2Art is not responsible for damages of any kind, including incidental and consequential damages.
Correction of Details
If your product cannot be repaired, we will replace your product free of charge.
When You Need Service
Please contact our support centre to obtain an RMA number and return instructions.
How Country and State Laws Relates to the Warranty
This warranty gives you specific legal rights. You may also have other rights that vary from country to country and from state to state.

If you would like to return a product, start the process by emailing us at This allows us to see if there is something we can do before returning the product such as a feature you didn’t know about or send you a return label. We don’t require an RMA number but do ask you to contact us to initiate the return.

Products bought from can be returned within 30 days of the original purchase date provided they are unused, undamaged and in the original product packaging. If a product does not meet these requirements we reserve the right to deny the return if we feel that it is warranted.

Who pays for shipping? In the event an item is damaged during transit etc, CO2Art will provide you a shipping label. If you are returning an item for another reason, it is your responsibility to get the item back to us safely. If it is a high-priced item we recommend a tracking number.

Items that go on sale after you purchase them. We will honour a sale price up to 7 days from the day you purchased your item, this is the day on which the order was placed.

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