Drop checker kit

With the “Drop” CO2 tester kit you have everything to measure the CO2 value of your tank. Just look at the color: Is it light green? Then your CO2 is fine! This CO2 tester kit is ideal because:

  • Everything in 1 kit to start measuring right away
  • Looks very stylish in your tank & almost invisible
  • Very sturdy laboratory glass: does not break easily
  • Easy & quick to clean
  • Very easy CO2 measurement: healthier aquarium plants

Do you dream of a beautiful, green planted tank? Then you need to provide good CO2. This kit will help you do just that.

Price range: €16,00 through €20,00
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THE KEY BENEFITS

Everything in 1 kit

Made of strong glass

Gemakkelijke setup

Easy to measure CO2

CO2 for a healthy planted tank

Do you have a planted tank and you use strong aquarium lighting? Then it is important that you add enough CO2 to your tank. Because without CO2, your plants will grow poorly, they will start to detoriate and then: algae!

Measure your CO2 properly and you can create the tank of your dreams.

hoe werkt PlantedBox

Measuring CO2 becomes a breeze

But how do you know if you have enough CO2 in your tank?

Well, this drop checker kit makes it very easy to measure the CO2 in your tank. You hold the checker upside down, with the open neck facing up. You then add the blue drop checker mix via the handy dispensing bottle, and then you carefully turn your drop checker over and place it in your aquarium.

After a few hours, the liquid will change in color. Does it remain blue? Then you have a CO2 deficiency. Is it yellow? Then you have too much CO2. Is it green? Fine, then you’re about right (+- 30ppm).

Easy, right? 🙂

Free advice tailored to your aquarium

Are you having problems with your tank? Are you struggling with algae and want some advice? Download my ebooks or read the tips on my blog.

FREQUENTLY ASKED QUESTIONS

What is included in this drop checker kit?

This drop checker kit includes:

  • 1x “drop checker”
  • 100ml drop checker mix

100ml of drop checker mix will last about 33 weeks if you change weekly. Nice and long.

How do you place the drop checker in your aquarium?

1. Turn the drop checker upside down
2. Add the blue drop checker mix until halfway down the drop checker
3. Now carefully turn your CO2 continuous test over & place it in your tank

When do you know you have enough CO2?

It’s very simple. Just look at the color of the solution:

  • Blue: not enough CO2. Carefully (!) inject some more CO2 into your tank.
  • Green: OK, but a little more would be better
  • Lime green: OK
  • Yellow: too much! Add less CO2 or put more oxygen into the tank

That’s it!

How to clean?

Replace the solution at every water change. Just turn the drop checker over & rinse it out with RO water  (not tap water, as it may affect the result). If necessary remove algae & clean the suction cup with some filter wool so it adheres well again.

Is the drop checker indicator mix toxic?

A few drops are not dangerous to your fish & shrimp, but avoid situations where you accidentally drop the whole bottle in your aquarium. Also – like with all other products – keep out of reach of children.

Should I flush the drop checker?

It is best to use RO water so there is no lime residue left behind that may affect the results.

WHAT DO OTHERS SAY ABOUT THE DROP CHECKER KIT?

Klantbeoordelingen

Maarten M.
Rating: 5/5
Maarten
Mooi en prima te vullen. En geen lelijk gezicht in je bak.
Tue Feb 24 2026 13:34:59 GMT+0000 (Coordinated Universal Time)
R.M. h.
Rating: 5/5
Top ding
Omdat de oude niet meer goed werkte deze besteld Super zuinig met co2 echt een aanrader
Tue Feb 03 2026 15:25:48 GMT+0000 (Coordinated Universal Time)
Richard B.
Rating: 5/5
Dit is een goede. Werkt top!
Deze kun je gerust kopen.
Thu Jan 01 2026 05:49:09 GMT+0000 (Coordinated Universal Time)
Andries L.
Rating: 5/5
Co2 tester kit
Snel geleverd. Zeer tevreden met het product.
Tue Nov 11 2025 08:40:27 GMT+0000 (Coordinated Universal Time)
Olof V.
Rating: 5/5
Doet wat het moet doen
Super blij met deze Co2 test , ziet er mooi uit in mijn aquarium .
Sun Oct 12 2025 09:01:26 GMT+0000 (Coordinated Universal Time)