OCTO Calcium Reactor

Regular price $789.00

In Stock

  • FREE Delivery over $100


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 


Technical Data

1. Calcium Reactor

Product Wet/Dry Pump Power Diameter Footprint Height Media Capacity
W mm inch mm inch mm inch L US Gal
CalReact 140 Both 25 140 5.5 310 230 12.2 9.1 580 22.90 3.90 1.00
CalReact 200 Both 40 200 7.9 385 270 15.2 10.6 580 22.90 7.90 2.10
CalReact 220 Both 70 220 8.7 420 280 16.5 11.0 580 22.90 9.30 2.50


Product Wet/Dry Inlet/Outlet Size Tank Volume Feeding Pump Suggestion
CalReact 140 Both ø6.3 mm(1/4″) 400-800 106-211 500-800 132-211
CalReact 200 Both ø6.3 mm(1/4″) 1100-1800 290-475 500-800 132-211
CalReact 220 Both ø6.3 mm(1/4″) 1400-2100 370-554 500-800 132-211

2. Circulation Pump

Product Model No. Wet/Dry Power Max Head Height Maximum Flow Rate
w m Ft. LPH GPH
CalReact 140 VarioS 2 Both 25 4.0 13.1 3000 792
CalReact 200 VarioS 4 Both 40 4.5 14.7 4000 1056
CalReact 220 VarioS 6 Both 75 4.9 16.0 6500 1720

Orders above $60 gets free delivery. Orders below $60 delivery is $15.

CBD / Sentosa / Jurong Island/ Orchard has an additional surcharge of $9.90.

Orders are processed within 3 working days.

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