CO2 scrubbing and piping in fresh air

reefkeep · Jun 15, 2023

My goal is to bring in fresh air to supply my protein skimmer. Of course I want to do this for pH reasons.

My fish tank room is in an interior room, as such it has no windows. It does, however have the 2 air handler for my homes air-conditioning system.

Is it possible to tap into the air that is being pulled into the HVAC system? Has anyone done this? Is it a bad idea? Any tips would be appreciated.

jda · Jun 15, 2023

Do you happen to have a co2 meter to know what the co2 level is in the room? You might not need it if your exchange enough air in the home and the HVAC moves it into that room. Meter is not expensive on Amazon.

reefkeep · Jun 15, 2023

I need it, I open the basement door and the ph jumps significantly. Today I used a c02 scrubber and that’s very effective but also costly.

hoffmeyerz · Jun 15, 2023

I don't know your system but depending on how the system and the line your are referring to are setup when the HVAC system is drawing air it will be drawing air FROM your skimmer line, the line will have neg pressure.
I have high CO2 levels in my house ( lots of people and pets) and run a scrubber. A bag of soda lime from BRS lasts me about 6-8 weeks. You can get it cheaper from vet supply places online.

bakbay · Jun 15, 2023

hoffmeyerz said:
I don't know your system but depending on how the system and the line your are referring to are setup when the HVAC system is drawing air it will be drawing air FROM your skimmer line, the line will have neg pressure.
I have high CO2 levels in my house ( lots of people and pets) and run a scrubber. A bag of soda lime from BRS lasts me about 6-8 weeks. You can get it cheaper from vet supply places online.

Are you doing recirculating CO2 scrubber? That should extend the life of the media and don't have to play with getting fresh air.

jda · Jun 15, 2023

I would cut a intake or vent in the ducts in that room - whichever is appropriate. Let the HVAC pull or push fresher air from your home into the fish room. We have windows open all of the time and home co2 around 425-450 and I had to cut a intake for my furnace to pull air into my fish room or else it was 750-900 co2 all of the time. A fan in the door works when we don't run the HVAC, or I can also just turn the fan on for the furnace.