CR100 4 inch Calcium Reactor reef octopus

REEF OCTOPUS CR100 4 inch Calcium Reactor


Rated for Aquariums up to 150 Gallons

This item ships directly from the manufacturer/supplier.

Availability: 5 in stock

Footprint: 9.5″ x 7.5″ | Body Diameter: 4″ | Height: 20″
Recirculation Pump: Aquatrance 1200

Quality, design and affordability define the Octopus Calcium Reactor series. Available in 3 different models that feature reverse flow water current for maximum water and Co2contact time with the coral media. All models come with PH probe holders to monitor Ph levels in the main reactor chamber and built in bubble counters to monitor Co2 drip rates.To help you meet the challenging task of maintaining alkalinity, calcium and trace elements , consider adding a Reef Octopus calcium reactor to your aquarium system.

How it works

A calcium reactor is essentially a chamber full of aragonite, which is the crushed skeleton of ancient hard corals. Aquarium water is pumped through this chamber along with pressurized carbon dioxide (CO2). The CO2 lowers the pH in the chamber to an acidic level which dissolves aragonite media into the aquarium water. In addition to dissolving the calcium, this process also dissolves nearly all the minerals and trace elements the coral used in order to grow.

Automated Calcium and Alkalinity supplementation – When set up properly and used correctly, a calcium reactor can maintain or increase calcium levels with little to no maintenance.

Calcium/Alkalinity Demand

– 120 Gallon– Light Demand | 100 Gallon– Medium Demand | 75 Gallon– Heavy Demand

Techinical Specs

Body Size: 4in
Footprint: 9.5in x 7.5in
Total Height: 20in
Media Capacity: 1.5L (.39gal)
Inlet Size: 1/4in
Max Feed Rate: 150GPH
Note:Suggest a feed pressure slightly higher than a full flowing influent

Recirculation Pump Information

Reef Octopus Aquatrance 1200 water pump
Wattage: 15w

Warranty –1 year warranty on pump and 1 year on reactor body

OCT-CR100 Assembly Diagram


1000 mls, 125 mls, 250 mls, 500 mls

Why Buy From ReefBum?

Number one, I have been a hobbyist for over 25 years who wrote a book on reef keeping best practices……so I can leverage this wisdom to provide expert advise on equipment purchases.

Secondly, I am the sole proprietor and employee of this company who can be contacted any day of the week to answer your questions about equipment sold on Therefore, you will always deal with the same person who actually uses the equipment you buy. And if I don’t have an immediate answer I can reach out to the manufacturer to get an answer….I have direct communication pipelines with all of them.

Yes, I am a “mom & pop” shop that will not always beat pricing from the “big box” online reef stores. But think of me as your personal reef tank concierge who is always on call to help figure out a problem or just chat about reef tanks. Now that’s priceless!

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