OCTO Calcium Reactor (3 models available)


OCTO Calcium Reactor (3 models available)

“An ideal solution/upgrade for the discerning hobbyist.”

Model No.: CalReact 140, CalReact 200, CalReact 220

Features & Benefits

  • Controllable and variable speed DC pump for energy-efficient and silent operation
  • Reverse flow and CO2 recirculating design
  • Precision effluent control valve
  • Built-in bubble counter for monitoring of CO2 drip rate
  • Probe holder with plug *
  • High quality handmade solid cast acrylic construction
  • Removal lid for easy maintenance

* Does not include PH probe.


An ideal solution/upgrade for the discerning hobbyist

OCTO CalReact features high-quality cast acrylic body construction, a PH probe holder to allow constant monitoring of water alkalinity (PH level) with the use of a PH probe (sold separately), a built-in bubble counter for CO₂ flow rate calculation, reverse water flow for CO₂ recirculation to maximise contact time with the coral media which produces CO2.

Powered by our VarioS DC pump which features a pinwheel impeller, a detachable controller, high quality ceramic shaft and bearing to reduce wear and tear, and the latest variable speed flow technology for refined control, enhanced performance, energy-efficiency and safer operations.

Unlike the vast majority of circulation pumps which uses alternating current (AC), our VarioS pump boasts several key advantages over traditional AC pumps, namely, higher energy efficiency, safer operations at a working voltage of 24V and most notably, the variable speed control to adjust the ideal mix of air and water flow into the skimmer.

Note: Above models are not pressure rated pump . This pump is not for second floor applications or to feed Beckett or downdraft skimmers where constant pressure is required.

How it works

A calcium reactor is essentially a chamber full of Aragonite which is natural form of carbonate mineral, or commonly known as crushed hard corals. Aquarium water is circulated through this chamber along with carbon dioxide (CO2). The CO2 lowers the pH in the chamber to an acidic level which dissolves the carbonate minerals into the aquarium water. In addition to dissolving the carbonate minerals, this process also dissolves nearly all the minerals and trace elements the coral needed in order to grow.

Automated Calcium and Alkalinity supplementation – When set up properly with external controller and probe. These perimeters can be pre-set with very little monitoring and maintenance.

Available in 3 models – CalReact 140, CalReact 200 and CalReact 220.


– 2 years for pump motor only

– 1 year on reactor body 

What's included

Article CodeItemsCalReact 140CalReact 200CalReact 220
Model No.QtyModel No.QtyModel No.Qty
aPH Probe Holder111
bTop Cover111
dO Ring111
eReaction Chamber111
gCross Connection111
hO Ring111
iO Ring222
lRubber shim111
mO Ring111
nWater PumpVarioS 21VarioS 41VarioS 61
oValve 01222
pCO2 Check Valve111

Technical Data

1. Calcium Reactor

ProductWet/DryPump PowerDiameterFootprintHeightMedia Capacity
WmminchmminchmminchLUS Gal
CalReact 140Both251405.531023012.29.158022.903.901.00
CalReact 200Both402007.938527015.210.658022.907.902.10
CalReact 220Both702208.742028016.511.058022.909.302.50


ProductWet/DryInlet/Outlet SizeTank VolumeFeeding Pump Suggestion
CalReact 140Bothø6.3 mm(1/4″)400-800106-211500-800132-211
CalReact 200Bothø6.3 mm(1/4″)1100-1800290-475500-800132-211
CalReact 220Bothø6.3 mm(1/4″)1400-2100370-554500-800132-211

2. Circulation Pump

ProductModel No.Wet/DryPowerMax Head HeightMaximum Flow Rate
CalReact 140VarioS 2Both254.013.13000792
CalReact 200VarioS 4Both404.514.740001056
CalReact 220VarioS 6Both754.916.065001720

Explosion Charts


Not Available

Accessories / Parts

Not Available