# DIY Drop checker using a fermentation air lock



## Tom Higgs (Mar 2, 2006)

Was looking for a cheap way to make a drop checker.... realized that one can be easily made with a fermentation airlock used for homebrew. All I had to do was seal the top down, and seal the holes with silicone. So far I havent been able to find a suction cup holder, so for now I just used a cable tie and strapped it to my filter feed tube.

Just hooked it up during a water change, so pH is a little high; will see how responsive it is.

Here is a link so you can see what it looks like; only 0.99c;

http://www.fermentationtrap.com/1401.html


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## Tom Higgs (Mar 2, 2006)

Worked great.


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## Tom Higgs (Mar 2, 2006)

Actually looks like it took about 36hrs to equilibrate fully, so not a device for fast results...but for finding out where you are co2 wise, it's a pretty cheap device


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