CO2 scrubber media

[kdtorgy]

I'm wondering the feasibility of using only NaOH pellets as the scrubber media vs. NaOH/Ca(OH)2 mixture sold by various aquarium supply sites. I've seen a few studies that show sodium hydroxide is a better scrubber than calcium hydroxide. Thoughts?

 

[Randy Holmes-Farley Verified Community Expert]

I'm wondering the feasibility of using only NaOH pellets as the scrubber media vs. NaOH/Ca(OH)2 mixture sold by various aquarium supply sites. I've seen a few studies that show sodium hydroxide is a better scrubber than calcium hydroxide. Thoughts?

It will work, but not nearly as efficiently as soda lime because the soda lime precipitates calcium carbonate, while sodium hydroxide only make sodium carbonate.

The pellets will liquify, so you end up bubbling the incoming air through a liquid.

These have more:

https://www.reef2reef.com/threads/practicality-test-of-co2-scrubber-with-sodium-hydroxide.798573/
https://www.reef2reef.com/threads/h...r-soda-lime-co2-scrubber.810904/#post-8746029

 

[kdtorgy]

I was wondering if the liquidation of the sodium hydroxide would be a problem. I've got a recirculating CO2 scrubber/skimmer set up. When I replace the CO2 media, pH is between 8.1 and about 8.2. After a few days pH drops to 8.0 to 8.15. I wouldn't think the media would be exhausted so quickly. I am using the BRS CO2 scrubber so the quantity of media is not huge but my system is around 140 gallons so I thought it would be sufficient. Maybe I have a leak in the recirculating system so air is getting in or is it possible I'm getting a lot of CO2 dissolved in the tank water which is exhausting the media quickly. I do live in a new house with four other people, two cats and a dog.