I have this same calcium reactor. First off the Aqualifter isn't going to give you enough air for the neutralizing chamber. The smallest air pump you can use is a Coralife Luft pump, it's around 45.00 and you can get them on ebay. Secondly, you do not need an AquariumPlant.com regulator with solenoid, all you need is a regulator, such as the Tunze, they are cheaper around 100.00. With the Aquariumplant regulator and the CO2 sensor/controller, you are not getting the proper amounts of CO2 in the reactor to break down media. Off a regulator, you have the tubing go to the controller, from the controller, it feeds to the reacor. You run the reactor with two timers. Depending on the amount of SPS you can run it 2,4,6,8,10 hours a day. This is how you would set it. Just set the timer for the controller, to turn on for 2 hours. Have the other timer hooked to the circulation pump, and run that for 2 hours and 15 minutes. The reason you run the circulation pump for 15 more minutes, is to help degas the reactor of any CO2 or O2. Each cycle should last 2 hours, depending on your tank, you can run one, two, three or more cycles. Be warned, that you need to start slowly. This reactor has the capability to raise your alk immensely.
Now for the regulator, I would open it up so you have a lot of bubbles going into the reactor. When CO2 enters the reactor, you will see the far right chamber where the bioball looking things, waterline drop. When the water lowers enough, the CO2 sensor, will detect it, and the controller closes the valve to stop injecting the CO2 into the reactor. I would also recommend teeing off the return line to ensure proper ml/minute rate. You will see that your problem was probably not injecting enough CO2. Sell the Aquarium plants regulator, buy a cheaper Tunze, and get yourself a Luft pump or larger. This Calcium Reactor is totally set it and forget it. Just remember to add media when you see it drop 3/4 of the amount you place in there.
