Glass CO2 Drop Checker Aquarium Hang On CO2 Monitor CO2 Detector for Aquarium Planted Tank

I wanted a small size drop checker for my 2g nano tank and this one is perfect. As a back up I also ordered the normal suction cup drop checker and it was way too big and took up too much valuable real estate in my tank. The only issue to be aware of with these external hanging drop checkers is the entry point is much smaller than regular fluted drop checkers so every now and then I find a co2 bubble blocking the entry point which causes the reactive liquid to turn yellow (since no oxygen is able to enter). Your best bet is to place this drop checker away from your diffuser so bubbles to float directly into the drop checker.

You have to shake it to remove the tension to get accurate readings a few times a week,

This product is probably made for tanks with rim. There is no way the size is as described. It’s way bigger and too far apart. I have a rimless tank and this is way too big. Wish it was a smaller in between so it wouldn’t look so weird on the tank. I’ll be returning it.

These things are very small. The pictures don’t really show just how small they are. The amount of gas exchange for such a tiny surface area probably makes these essentially useless as indicators of CO2 levels. They will likely be way behind the actual CO2 concentration.

So cute and functional!