Final adjustments: Once the reactor has been set up to achieve the optimum effluent alkalinity you will need to tune the reactor for system demand. With the reactor running check your systems alkalinity, write down the results and check the systems alkalinity again 24 hours later. If your systems alkalinity has dropped you will need to increase the output of the reactor to match demand. To increase the alkalinity, adjust the peristaltic dosing pump to increase the flow rate by 1 drip per minute more than the current drip rate. Check the aquarium alkalinity again 24 hours later and if needed follow the steps above to increase the reactors output again. Repeat these steps until you find the aquariums alkalinity and Calcium demands are being met by the reactor. It is important to test the aquariums alkalinity 24 hours after any adjustment so demand can monitored and the reactor adjusted to suit as above.
Key points: If you make adjustments to increase or decrease the calcium reactor effluent rates you might also need to make appropriate adjustments to the CO2 bubble rate to maintain effluent pH. Set the effluent flow rate and effluent pH to keep up with system demand, if the system alkalinity decreases then increase the effluent drip rate and visa versa. Always specify the correct size calcium reactor for the aquarium, when you reach the maximum effluent rate for the reactor the effluent dkh will drop regardless of pH or CO2 input. It’s better to over spec a reactor and run it at half duty if need be than choose one that’s too small and struggle with it. Adjust the CO2 bubble count as low as possible to achieve the desired reactor pH if using a controller to prevent frequent on/off cycling of the solenoid. Leave at least an hour after adjusting the reactor to test effluent dkh. Make sure all CO2 fittings aren't leaking and a check valve is in place to stop tank water entering the solenoid.
After running this setup for a couple of weeks, measure the parameters weekly to determine if the tank demand has changed. In order to adjust the parameters up or down, just turn the knob on the calcium reactor dosing pump. This setup is very stable and easy to maintain. I rarely touch mine and it has been running this way for years. I have to add a cup of kalk once a week to the kalk stirrer, I add media to the calcium reactor every 2 months or so, and I re-fill the CO2 tank every 4 months. One thing I will say is, buy good peristaltic dosing pumps that have adjustable flow rates. They can be found on Ebay for less than $150.