Need frsh O2

[IslandReefer]

My fishroom was once called a furnace room with included natural gas hot water heater....hense lots of CO2.
My strategies include:** exhaust fan (bathroom fan plumbed into old dryer outlet
**2in vinyl hose to the air intake of my skimmers beckett and through the wood frame of a basement window.
If this is not enough, I will raise the ORP by running low dose ozone....but fresh outside air and room exhaust should be enough....
Any more ideas??