Diy co2 scrubber question

criticalencore · Aug 17, 2025

I was getting notifications from my Apex everyday basically for my pH. It would drop pretty low (7.6ish and not really get over 8) but was consistent. I was hoping a co2 scrubber would keep it higher. My tank is a 40b with a 29g sump. I was using a cheap air stone skimmer which was actually making a good bit of skimmate. I had an ASM g2 laying around so I ordered a new Sedra for it to use to get air to the venturi from the scrubber.

The co2 scrubber i made is a large Chinese takeout soup container. I drilled like 5 holes in the lid and put a barb in the bottom with the hose running to the skimmer venturi. I filled it about halfway up. I had saw some people saying moist air works better and saw some have like a filter before the output side. I have a couple questions I guess since it is working seems like

Will the media last longer if I use a barb fitting on a new lid instead of the holes I drilled in it currently?

Is it worth putting a barb on the skimmer cup to get moist air instead of just air from the room?

Is more media better in the scrubber or if i use less do i just need to change it more often?

Do I wait for all the media to change color before I replace it?

Thanks. Im sure i have more questions I just can't think of at the moment. Ill see if I can post pics from my computer when I get in the house later

Dread Pirate Dave · Aug 17, 2025

Moist air will make the soda lime last longer and it seems to work better.

You don't want the media to get soaked and you don't want to accidentally pull any into your tank.

These scrubbers use a condisation trap to help avoid this.