Calcium Reactor Tuning Question

coralcrazy · Jun 19, 2015

I am having some difficulty tuning my calcium reactor and need some forum help.
Details:
Aquamaxx S1 Calcium Reactor
Carbon Doser Regulator
150 Gallon Tank (Heavily Stocked with corals)

Been running now for about 5 days. I am having issues keeping my alkalinity up and calcium down. PH of affluent is 6.6. I am dosing 1 bubble per 4 seconds of affluent and C02 at 1 bubble per 5 seconds. All of this is being controlled via Apex.

Did some test today and found that my Calcium was at 560 and Alkalinity was at 94 ppm. Test from two days ago was Calcium at 420 and Alkalinity at 110. I also noticed the ph in my tank slowly dropping from 8.3 to 8.0 -8.1 since I've connected it. Im not sure how I can get this dialed in. Any advice would be a huge help.

Randy Holmes-Farley · Jun 20, 2015

Forget calcium. You can only tune the reactor with either calcium or alkalinity, and alkalinity is much more sensitive. So tune the reactor to meet the daily alkalinity needs.

Calcium released will follow almost exactly with the alkalinity released (in the fixed ratio in calcium carbonate), and if calcium is too high, it is high for other reasons, such as your salt mix.

FWIW, calcium did not jump from 420 to 560 ppm. That is testing error. Alk would have had to rise by 20 dKH in the same period for that to happen.

The pH does drop with a CaCO3/CO2 reactor. That is a drawback of this method. Some people use limewater (kalkwasser) along with the reactor to help keep up the pH.