[miles]

I use an Aqua Medic 1000. It is an in-line reactor that is connected to the outflow from my filter. It is really efficient. I guess that it dissolves close to 100% of the CO2 output from my regulator. I started with an Eheim CO2 diffuser and it was… well not very efficient. With the Eheim I had to refill my 5# CO2 bottle in about 3 weeks. I have no clue how long my bottle will last with the Aqua Medic. I've had it for 4 weeks and there has been no significant decline in CO2 pressure yet.

BTW this reactor is recommended for use with a pH controller. Because it is so efficient you can easily overdose your tank if you don't have a feedback system to control the flow.

having to refill a 5lb bottle in 3 weeks sounds like you had a big leak somewhere.