You demand is pretty high and that drop is too much. I reread what I posted and was mistaken when I said stop all dosing. I should have specified that after the 24hr test you dose them back up then test again in 24hrs. I apologize for not covering that correctly.
Seeing as you've confirmed a +1dkh drop a day restart the dosing and get the parameters back up to alk 9~9.5dkh and cal 425~450.
Once the parameters are where you want them pick a time of the day you will be able to test at the same time for several days. A half hour before you set time start the co2. This will give the reactor time to get the ph down. A half hr later at your time time turn off the dosing. Now follow these steps per Acroholic:
6. Let the controller run like this at these settings for 24 hours. After 24 hours, test your calcium, alkalinity and magnesium levels again. If they are close to your initial levels, wait another 24 hours and test the next day. If you find your levels dropping or rising, refer to 7 below.
7. What control parameters to adjust:
(You using a peristaltic pump so you can disregard this part.)
a. I have found for the past three years that an effluent rate of 50-60 ml/minute and a bubble count of 60-90 bpm (bubbles per minute) is perfectly fine and these two parameters do not need adjusting. If your CO2 Bubble Rate is near 90 bpm, make sure you are not overpowering the reactor's ability to absorb all the CO2 you are feeding it. You are using too much CO2 if you see gas collecting at the top of the reactor. Adjust it down to the middle or lower end of the bpm range if you see this. Calcium reactor output can change over time due to the effluent out line getting clogged or calcium carbonate or salt collecting inside or at the tip of the effluent out tubing. I have to adjust mine back to a fast drip every few days. Bubble counts stay pretty steady and do not need adjusting after you are dialed in.
b. The easiest way to adjust a calcium reactor for more calcium, alkalinity and magnesium in the effluent is to change the controller setpoint pH setting. I have just found it easier to keep the bubble rate and the effluent rate constant and adjust the controller setpoint up or down as needed. If you need to raise your levels a bit, lower your controller setpoint by .5-.1 units of pH and test for a few days. The lower the setpoint, the more CO2 gas will go in, dissolving more media, and releasing more calcium, alkalinity and magnesium into the tank. If you see your calcium, alkalinity, and magnesium levels rising, raise your pH controller setpoint up a bit until you see consistent test results for a few days. This decreases the amount of CO2 entering the reactor, and lessens the amount of media being dissolved.
c. The end objective is to get several days of constant readings without much drift up or down. When this is achieved, you can readjust the tank water calcium, alkalinity and magnesium levels to what you want with additives, and the reactor should maintain those levels for you. You want the reactor to release calcium, alkalinity, and magnesium at the same rate it is used up in the reef tank.
8. Your calcium reactor is now initially dialed in. Regardless of what method you use, regular testing for Ca, KH and mag is needed, every 1-2 weeks. After you get some experience using the reactor, you may increase this testing interval to your own comfort level.
