A reactor with more
volume allows you to increase the effluent rate. You have to aim for a minimum reactor-time of
5 hours(at pH 6.4), to get the optimal saturation of your effluent.
Increasing the effluent rate won't beneficial at some point anymore because it isn't enough saturated. You can lower the pH but you end op with excess Co2 and pH issues in the tank.
So... For example, if you drip 25 ml a minute, you need at least a reactor with (25*60)*5 = 7,5 liter (2 Gallon) for optimal results (and use all the Co2 you put in).
Loading the reactor to the top with media isn't a good idea because you decrease the reactor (water )volume. 1/3 filled is enough.
A large reactor controlled by a pH controller is beneficial for a stable Ca and Alk supply, and can keep up with the demand as the tank matures.
You can also simply enlarge the volume of the reactor to keep up with the demand.
I by-passed a 25 Gallon drum to my Schuran Jetstream II to increase my reaction time. I never had any pH issues because all the Co2 reacted with the CaCo3 and it was able to keep up with HUGE demands
Hope this helps:thumbsup:
Leonardo