Ask HN: Is it possible to make a Carbon Capture device at home?

Possibly, but isn't the first question to be answered this: is it even possible to make a carbon capture device, period?

Other than flora and fauna, I'm not sure that humankind has actually developed a net negative carbon capture device. Have we?

If we have, I'd be super duper excited to see some links to examples.

Do house plants count?

If you want something more aggressive, I would explore growing high surface area algae in a fish tank. You can probably even make it look nice.

If I was going to homebrew something I would try encouraging algae growth on aquarium bio balls, probably with a nice waterfall for circulation.

If you could encourage algae growth on even something like this it could get you started..

https://www.youtube.com/watch?v=iXhp3W7jhEQ