I still use one ladder (Hagen) in my 33 gal. Iím just able to maintain good CO2 level, without wasting CO2 in a high bubble rate.
Soon I will try a home made reactor.... to be able to have more control over CO2
This reactor look good but if you say that it donít work as well as your 2 ladder. That just show that sometime simple things work.
The only advantage of the reactor will be the surplus of water movment you create (help for the absorption of nutrients, (Prandtl boundary).