Which filter media to remove to prevent Co2 "burping"

[Chris Jackson]

Basically only a certain amount of gas will dissolve in the filter with any efficiency after that increasing the co2 bubble rate will not achieve anything because it will be beyond the filters ability to absord and so you'll just be wasting gas and get loads of burping. If a drop checker is telling you your co2 is fine, and your plants are growing then there should not be a problem if not then maybe it's time for a diffuser...
Otherwise there maybe some design querk with your filter trapping gas and giving the burp issue.

 

[Sacha]

Just to update.
I am going to move the inline diffuser back onto the out- pipe. No matter what bps I have, the filter still burps every few minutes.