Calcium Reactor Setup


Reef enthusiast


Geo's Reef
  • All cell cast acrylic construction
  • Clear lid to view proper O-ring seal
  • Key hole slot for lid removal
  • Micro ball valve effluent control
  • Eheim 1048 pump, bolted to base plate
  • pH probe port in lid
  • pH probe adapter included
  • Auto fill bubble counter
  • 10 x 9 foot print, 24" overall height
  • Holds 12 pounds of media, we recommend large grain schuran type
  • For reef aquariums up to 350 gallons



RF Deluxe CO2 Regulator with Solenoid

RF CO2 regulator features:
  • Integrated 110V German solenoid valve Integrated precision needle valve
  • Preset working pressure gauge making fine tune easy
  • Compact and chrome plated body
  • Compatible with standard US CO2 tanks



Aquacontroller Junior

  • Monitor: pH, and Temperature
  • Control: pH, and Temperature
  • Optional Computer Interface - works With AquaNotes NOW!
  • 1 Optional External Switch Input
  • Timers
  • Simulate Sunrise/Sunset
  • Simulate a Moon Cycle
  • Control Powerheads/Pumps (Wavemaker)
  • Hardwired or X10 Control Options
  • Programming Language
  • Alarms
  • Perform Datalogging
  • Flash Memory for easy Firmware Upgrades
  • LCD Display
  • Display Lock with password protection
  • Battery Backed Real Time Clock



MaxiJet 1200

  • High performance with low power consumption
  • May be used externally or submerged
  • Waterproof rotating water outlet
  • Silent, versatile, low maintenace
  • Protected motor will not overheat
  • Tank Mount Bracket
  • UL Approved
  • Directional Flow Flap




Schuran Media

NO Picture - Used to help maintain Magnesium
Dolomite - Calcium Magnesium Carbonate - CaMg(CO3)2


CO2 Tank

I just got mine from a local company since you will need to have it filled locally anyways. I got a 20lb Aluminium Tank.



I setup the Unit in the Garage next to a 30 gallon trash can just to test for leaks etc and am extremely glad I did. Over three days it revealed the following issues.

  • Inlet of the EHIEM 1048 pump had a slow leak (Fixed with teflon tape)
  • Outlet of the EHIEM 1048 pump had a slow leak (Fixed with teflon tape)
  • CO2 line into the Unit had a small leak (Fixed with teflon tape)
  • Effluent line out of the Unit had a small leak (Fixed with teflon tape)

The above small leaks were one to two drops over 12 hours, tiny leaks that would be harder to find and fix if not tested before hand and in an environment where I could inspect from 360 degrees.

CO2 Line:
I highly recommend spraying the entire CO2 line with soapy water to check for CO2 leaks. I had not tightened the regulator onto the tank tight enough and noticed my high pressure side had dropped by 5 PSI. I never heard a hiss or anything, so its a good idea to test upfront.


* = Indicates CO2 Completely Off
+ = Effluent Wide open

-- Trying to get things to settled down.

TANK Effluent
Date Time PH Alk(dkh) Calc PH Alk(dkh) Calc
*+9/24 11 AM 7.77 7.7 390 7.42
*+9/24 12 Noon 7.8 --- --- 7.77
*+9/24 1 PM 7.85 --- --- 7.9
*+9/24 3 PM 7.95 8.4 --- 8
*+9/24 5 PM 7.95 7 360 8

--I had unhooked my Kalk Reactor while doing this and started noticing the alk and calcium drop.

9/24 5:30 PM The unit was set at a rate of 25 ml per minute effluent with a PH of 6.9.
9/24 8 PM 8 9.1 400 6.9 30.8 500
9/25 5 AM 7.8 7 360
9/25 6 PM 8.1 7 360 6.9 16.8 480
9/25 6 PM Adjusted the effluent PH to 6.8

9/25 9 PM 8.1 7 360 6.8
9/25 9 PM Manually added Calcium and Alkalinity to adjust the levels up.

9/26 8 AM 7.9 9.1 380
9/26 5 PM 8.1 8.4 360 6.8 16.8 480
9/26 5 PM Reduced the Effluent PH to 6.7

9/26 10 PM 8.1 8.4 360 6.7 16.8 480

9/27 8 AM 7.9 8.4 380
9/27 8 PM 8.1 8.4 380

9/28 7 AM 7.9 8.4 380
Last edited:
Obviously using spaces to make columns won't work. I'll correct this later. I'm more less creating a log so I can create an article for anyone interested in doing setting one up in the future.
You're negative comments don't want to make me continue going out of my way to update this to benefit you.

I'm only putting this here so you guys can learn from my mistakes, so :bowdown:.

Because we all know when it comes to CA reactors and this club no one had a clue, including myself.
does anyone else ever get tired of a certain member who will remain nameless thinking hes better than everyone else? momma always said "Pride comes before a fall" or in this situation a "crash"! Im predicting a crash in 4 days. and we know how these predictions are pretty reliable!
Where is the "Just Kidding"? First you call me a nerd now this...... don't make me start editing your posts again :).
Where (to skimmer discharge, else where in sump or straight to tank), and when are you sending your effluent from the reactor (night time, day time or 24 hrs per day)? How much CO2 are you injecting (bubbles per minute)? Are you using food service or welders supply CO2? Are you using this to replace Kalkwasser, are you using both (my preference) or were you using bottled calcium and buffer complexs before? Maybe you gave some of this info and I missed it. It would be nice info to know as it all makes a difference. Nice equipment choices! Will this site accept an Excell chart as a picture if scanned/converted to a jpeg format?
hey guys, this thread is a year and a half old. Brandon is still running the same calcium reactor and has had good success with it. I doubt he will respond because he doesnt monitor this forrum anymore. but I will call him and see if he can check your questions out and give you some data on his system. As for a few answers: he was running the reactor and a MRC kalk reactor for the first year, then he added the Geo Kalkreactor to replace the MRC. He had his tank crash for some unknown reason so he has removed the kalkreactor for now.
the efluent is a constant drip, and is dripping into the sump. as for bubble rate he is using the PH function on his aquacontroller Jr to turn the Co2 on and off. as for the grade, he had it filled with what I believe he called lab grade, maybe the same as food grade? it was more expensive whichever it was. and he got the better quality bottle as well I believe.
Hope this helps alittle.
As Brian mentioned the system has been setup for over a year now.

I've had great success with the CA reactor and would recommend it to almost anyone with a reef setup. That said I have recently had some changes in my setup.... i had what I wouldn't call a crash but a down turn in color and overall health which I beleive has been traced back to a low magnesium level 700ish.

I was running the Kalk along with the CA reactor to help maintain PH levels etc, but have since removed it as I don't think its needed. My effluent drips into sump at about 1 drop a sec. The bubbles are set to about one bubble a second also, but doesn't matter as it is controlled by a PH probe within the reactor connected to my Aqua controller JR.

As for the CO2 there were three offerings. Weld Grade, something in the middle and Medical Grade. I tried to get the medical grade but you can't unless you have some special paperwork etc.. The individaual said the only difference is the inside of the tank is lined with some type of bladder. So i got the highest grade I could not sure exactly what it was called (high grade, Lab Grade, etc) but it was not medical grade.

Hope this helps and if you guys have any futher questions please let me know.
Alaska is a bit different. At the welding supply houses here we have Welding Grade and Laboratory Grade, no medical grade that I know of. There is a difference in the amount of trace gases as most CO2 now comes from, believe it or not, power plants. They actually gasify coal and separate out hydrogen and CO2 for sale to offset the lesser amount of heating BTU's available for power generation after the processes energy intensive needs are met. This is a totally different processthan extracting CO2 from flue gases, which is full of all kinds os other stuff. However this new processes (from coal gasification) nearly pure CO2 is not used in the welding trade due to its higher value and higher costs. The chief use for the really clean CO2 is for use in carbonated beverages. Here in Alaska the soda distributors will sell the CO2 to you at a cost of $35 per 10 lb bottle ($70 deposit on bottle). A lot more expensive :twocents: than welding grade, here anyway. I take too many college chemistry classes in general to worry about gas access, but laboratory grade is more expensive here than beverage CO2.
I think I paid roughly 170$ for a 20lb bottle. Like I said not exactly sure what the grade was labeled, but it was something between welding and medical.
:twocents: Wow! Your not joking either, are you? Is that counting a purchase of the tank? Up here we just pay rental by the year and swap tanks. If we purchase tanks they hold it, inspect it, and charge for each inspection. (Planned discouragement I believe.) Bevearge companies are the cheapest up here. Tank rental at welding supply shops are about $40-50 per year wher as the beverage company just wants a one time refundable deposit.
The way they do it at the place i got mine from is you basically put down a deposit for the bottle.... then when you bring it back you get the cost of the bottle back.

If you bring it back for a refill then they just exchange your bottle for another one that is already filled.