Senzeal CO2 Drop Checker Glass Aquarium Monitor CO2 Indicator for Planted Fish Tank
$6.99
Price: $6.99
(as of Nov 07, 2025 08:29:46 UTC – Details)
From the brand
Senzeal
Senzeal can provide you with the best aquarium accessories, and we believe that our high-quality products will meet all your needs.
Aquarium Accessories
Aquarium Supplies
Aquarium Filters & Accessories
Aquarium Feeder
Is Discontinued By Manufacturer : No
Package Dimensions : 4.45 x 2.64 x 2.52 inches; 1.31 ounces
Item model number : SZLUS-0547
Date First Available : September 13, 2018
Manufacturer : Senzeal
ASIN : B0793M9K71
Best Sellers Rank: #95,013 in Pet Supplies (See Top 100 in Pet Supplies) #138 in Aquarium Test Kits
Customer Reviews: 4.0 4.0 out of 5 stars 170 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
CO2 drop checker made of high quality glass, use to measure CO2 levels at a glance.
Apply to: fish tank, aquarium, especially aquatic plants, tropical fish to watch and cultivate for fish tank. Monitor to be installed below the water surface about 10cm, it is recommended not to install too far from the refiner.
Monitoring CO2 levels in your planted aquarium is very important for the health of your plants and fish. Can keep the CO2 levels in your tank consistently by checking it regularly.
Easy to install and use: Make sure your test kit is clean. Drop 5 drops of CO2 indicator(not include) into the glass checker and use straw to fill the tank water with the test solution area to 1/2. Then turn the opening facing of drop checker down. Use a sucker to attach it to the side of your tank and wait for up to 2 hours.
Indicator color chance shows results: The CO2 indicator (not include) color is blue, when it is blue represented CO2 insufficient; Turns green, the balance of CO2; Turns yellow, means your tank has too much CO2. Make the necessary adjustments and test until you get green. (Note: Glass products are fragile, please be careful when opening the package and using the product to avoid injury.)
Customers say
Customers find the CO2 drop checker to be a perfect drop checker with good quality and stability, and they like its design. However, the functionality receives mixed feedback, with some saying it works well while others report inaccurate results. Moreover, the size is problematic as it doesn’t fit rimless tanks, and the suction cup quality and adhesive strength are also mixed aspects.
8 reviews for Senzeal CO2 Drop Checker Glass Aquarium Monitor CO2 Indicator for Planted Fish Tank
Add a review
Related Products
$6.99
Stephanie V. –
works!
works really well, i’ve only used one for about a year or so and it hasn’t broken or cracked like other reviewers mentioned. I think it helps to just leave it in an area with less clutter
Firpo –
Easy to read
I had a glass internal drop checker and I hated it. It would condensate and get algae and was hard to read. This one is clear and easy to read. The only issue is you have to maintain water level. If the water level drops below the bottom of the drop checker, it canât read the water ph. Also, I donât have a rimless tank and I had to drill the plastic rim on the inside to the tank to be able to get it over the side. I like this better anyway, as the drilled hole keeps the checker perfectly level and stable. I highly recommend this checker.
TB –
Works but takes 3x as long to show results
Works fine but it takes almost all day for it to show the same result as the normal sized drop checkers
Lakeisha G. –
Slightly disappointed
I wish these were wide enough to use on a framed tank. Every product out there that uses the overhang style are only designed for rimless tanks. The other methods suck because the suction cups fail or my fish keep knocking out the suction cup. I’ll keep searching for a wider U
Dan M –
Only suitable for frameless tanks.
Too narrow for a tank with a frame.
Luis Crespo –
Co2
Excelente
Justin –
The Perfect Drop Checker
This is my second drop checker since switching to a high-tech setup and love the design! My first drop checker was one of the traditional horn-shaped ones that sit inside the tank and broke when I went to move it, nearly cutting my hand. With this one, I can move it around the tank with ease, which was been super helpful as I was figuring out the best placement for my diffuser and HOB filter.
Echo November –
Holds firm, and it works. No solution included
I thought this came with the solution to add to it, but it does not. However, for the price I am not surprised. It was easy enough to make a 4KH solution and add some pH reagent to it. Fairly easy to fill, but what I am impressed by is the holding power of the suction cup. I’ve had more expensive equipment come with cheap suction cups that let go every couple of weeks. This one? It’s been about 2 months and I’ve only had to push air bubbles out twice. It is solidly attached. It’s easy to read so I know what my CO2 levels are at. Like any drop checker, it’s not instant and it needs a couple hours to read any changes in CO2 levels.Overall, I’d not only recommend it, but I will be buying more of these as I add CO2 injection to my other tanks.