This is one of those spots where you may need to do some looking and thinking on what's needed. How much we each need for CO2 is a variable that depends on lots of things. Are you pushing as much CO2 as wanted/needed and not getting more CO2 bubbles released into the tank than you like?
What we each like is part of the question. Do you like to see the sparkle from bubbles or do you want none?
Got too many bubbles, you need bigger. But if you want more , smaller is the way to go. The reactor is just a place where the CO2 can hang out while it is absorbed into the water. Too little space and it comes out in the water. In general, I would guess that you are on the small side.