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SeaBones Calcium Reactor v2
SeaBones Calcium Reactor v2
SeaBones Calcium Reactor v2

SeaBones Calcium Reactor v2

20 reviews
$ 469.99


Balanced replenishment of calcium and alkalinity is among the most important water quality corrections required for a thriving reef aquarium.  The SeaBones calcium reactor achieves this by liberating calcium and bicarbonate ions from aragonite media, typically old coral skeletons, using CO2 gas.  This process yields equal amounts of calcium and alkalinity added to your aquarium water with no by-product ions, unlike with two-part A/B solutions, which can throw off your system's ionic balance.

Once the reactor is installed and set to meet the calcium and alkalinity demands of your aquarium, it is a very hands-off system for continuous addition of these needed elements.  Since it operates continuously, calcium and alkalinity are added at exactly the rate they are taken up, resulting in very stable water chemistry parameters.  This is essential for the health of sensitive corals like Acropora sp. (SPS, aka Stability Promotes Success).  Again, this is unlike two-part solutions, which are often added all at once, causing a spike in calcium and alkalinity levels on a daily basis.

Back by popular demand (and some of you have been asking for a long time), our new version 2 SeaBones reactor takes advantage of the efficient design we developed for our Mutiny Ozone reactor, using a low power draw Sicce syncra pump to quietly and rapidly recycle seawater through a carbon dioxide internal atmosphere.  The coral bones media effectively acts as a diffusion chamber, creating a large surface area for CO2 to dissolve into seawater and react with the media.

Keeping the system simple, we selected a very tiny and energy efficient 12v DC feed pump, and matching drip nozzle that automatically sets the flow through rate at an ideal and consistent level.  This small pump is still capable of building significant internal reactor pressure, useful for helping dissolve CO2 into seawater.

Technical Data

Footprint with connected optional secondary media chamber: 12" x 7" x 21" tall.  Without the secondary chamber, the footprint is 7" x 7".

The secondary reactor chamber can be placed remotely for more flexible footprint options.

What's Included

Comes with main reactor, recirculating pump, feed pump, drip nozzle for flow control, and CO2 check valve.  The secondary chamber pictured with the main reactor is optional.

4 feet of tubing for reactor hook up are included, all CO2 safe tubing for water connections is included.

What's needed

A CO2 cylinder and regulator with bubble counter are required for operation but must be purchased separately.  We recommend the Aquarium Plants' Carbon Doser CO2 regulator.

We recommend chunky "coral bones" style calcium reactor media, such as Two Little Fishies' Reborn media.

Installation Guide


Customer Reviews
4.9 Based on 20 Reviews
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Christopher S.
United States United States

Great calcium reactor

Easy to set up and is working great!! One little small hiccup but customer service was great and had me running in no time

Wade B.
United States United States


Every thing about Avast Marine is top notch!

Andrew M.
United States United States

Calcium Reactor

Still in process of building but customer service is already above and beyond

Zach H.
United States United States

No bones about it, AWESOME!!

As always another Avast grand slam!! This reactor is well thought out and assembled perfectly. I really like that the Rector with 2nd chamber fits 8.8lbs of my favorite media perfectly. Hook up it awesome and the included feed pump makes dialing it in even easier! Thanks for another great product Avast!!

Avast Marine Works SeaBones Calcium Reactor v2 Review
Joshua G.
United States United States

Checks all the boxes!

From the small footprint and fantastic build quality to the ease of setup and simplicity of dialing in this was exactly what I was looking for! I have had multiple calcium reactors in the past and the thought put into this one far surpasses the others. All this on top of the extremely fast response from Avast when ordering has made my experience with them overall amazing. I look forward to using this reactor for years to come.