Biorock Experiments

(Cole Santos) #1

I found some interest here in 2015 in biorock accretion. I am about to start a series of tests I hope will allow the formation of island size structures. From my reasearch so far bio rock is stronger than concrete and was origionally developed for industrial use. It appears that the inventors have used it to create breakwalls and restore beach.

Several techniques i am theorizing will increase strength and accretion rates.

  1. Layering the electrode. I plan on adding layers of electrode as the process continues so that conductive material is always exposed during the growth phase.

  2. Increasing growth rates via increased surface area. More surface area means the holes close faster. I plan to test steel wool, hydrocarbonated biomass, 1 inch carbon fiber chop expanded steel, wire meshes, bug screen. another byproduct of using a fiber is that you are essentially creating a carbon fiber reinforced bio concrete.

  3. Materials I plan to test spray on carbon electroplate conductive base paint on various non conductive materials such as foam and plastics. I plan to use charred wood for electrodes as it is conductive. I have a hunch it will form within the wood fibers creating a synthetic petrified wood.

  4. Synergy. Im hoping that by doing all these things together it becomes feasable to acrete large strong hulls.

(.) #2

Sounds reasonable to me.

(.) #3

Char is the solid material that remains after light gases (e.g. coal gas)
and tar have been driven out or released from a carbonaceous material during the
initial stage of combustion, which is known as carbonization, charring,
devolatilization or pyrolysis.

And to use seaweed as a source of carbon.

(Chad Elwartowski) #4

Awesome. Welcome back.

I would love to hear your findings. When I move to Tahiti I hope to try to get biorock working for its properties in being beneficial toward coral growth. Would be good to compare notes.


It’s already working and the results are amazing.


Charred wood might be too soft of a substrate for building biorock hulls. A steel mesh armature (as the ones used in ferrocement construction) would seem to be more appropriate.

But, since the process is VERY SLOW, it might take decades to form a water tight hull, that’s the problem…

(Chad Elwartowski) #7

Yes, quite inspiring. Beautiful art underwater that promotes the wildlife.

(.) #8

I am glad to see that there are different directions. The ferrocement is a good way.

I am interested about the charred wood.

(Cole Santos) #9

Im not sure what your talking about the process is slow. Its prety decent. The growth is 2d so you just need to increase the surface area of the electrode to decrease accretion times for 3d structures. Charred wood would be used as a high surface area filler where you wish to increase the thickness of the hull. So youd have a super structure of rebar, wire screen for hull walls, steel wool to thicken walls, and carbon as mass filler.

(Nicole Helgason) #10

Hi Cole,

I just joined this forum and this is the first topic I see!
I would be interested to see your results.

The coral projects which are using this technology don’t seem to benefit in the long term. As for using this for industrial use, I cannot say.

Here what I know about BioRock coral projects. By passing a low voltage current through seawater, this causes dissolved minerals to crystallize and to grow on the structure. It is easier for coral larvae to settle, and corals may accrete to the structure faster, but overall more time and money is wasted installing and maintaining these cumbersome systems as opposed focusing on growing corals.

Long-term the structure fall apart and can collapse under the weight of coral. Underwater projects look like a mess with wires hanging from the surface, collapsed frames, discarded frames, and frames that electricity has been cut off. Often these relics are now covered in sponges and seaweed. Not something they show you with a group but visit the first ever biorock project in Permuteran by yourself and you don’t have to go far to see what I mean.

In all the years the technology has been around there is very little scientific evidence that it benefits coral growth in the long term. And, all you have to do is look at the marine aquarium hobby. If this technology worked to grow corals bigger, faster, stronger, everyone would be doing it.

As for breakwalls and restore beach that I don’t know, and for the context of putting it on a hull, I am curious to see if this could work. You are not looking to grow corals because there is limited light, so perhaps just to create a solid mineral layer under a boat this could be an interesting idea.

(.) #11

I did some biorock experiments. The formation of Mg(OH)2 and Ca(OH)2
is not limited to the cathode, but there is precipitation around the cathode.
I tried to place an electrode in concrete, and the accretion goes on.
I thought about placing an electrode in foamed concrete, and it went OK.
I tried to fuse two foamed concrete blocks by placing an electrode between
the blocks.

All these processes require electrodes. Producing electrodes in open ocean
environment can be difficult. The simples way, I see, is seaweed and charring
seaweed to use carbon electrodes for the accretion.

For me, this was a missing link; to produce the electrodes in open ocean environment.

Thank you for the tip.

(.) #12

Biorock/seacrete and three dimensional printing:
A nozzle with seawater dripping from it, and two electrodes on the
two sides of the nozzle. The two electrodes are fed from a solar panel
with about 12V DC. Every time the nozzle drips, the seawater drip short
circuits the electrodes, and completes the circuit. At that point Mg(OH)2
and Ca(OH)2 precipitate in the drop. When the drop falls down the water
drains away and leaves a solid deposit. Later this solid deposit of Mg(OH)2
and Ca(OH)2 absorbs CO2 from air to form CaCO3 and MgCO3 and the
material becomes similar to limestone or seashell kind of material.
If this dripping nozzle with the electrodes is placed on a 3D printing moving
mechanical device that is controlled by a computer; limestone kind of
structure can be 3D printed from seawater using solar electricity.

Something similar:

The solution reacts with carbon dioxide in the air and precipitates calcium carbonate.[5]
Ca(OH)2(aq) + CO2 (g) → CaCO 3 (s) + H2O (l)
When this solution drops down it leaves behind particles of calcium carbonate and
over time these form into a stalactite


(Cole Santos) #13

Ha sounds good except for salt water and electronics…


I’m talking about the accretion process being slow.

How “decent”? Links? How long would it take to build a 2" thick hull? Did anybody already build a seacrete hull that float without leaks, is solid and can take the pounding of the wave?


I would gladly participate in such project, money and work.

A small floating seastead could be built to host an array of solar panels and wind generators to provide 12 v for the accretion process and as a “visitor center” for a snorkeling business on such “biorock reef”, I guess.

(Cole Santos) #16

This is one of the oldest papers.

the second link is more relevant. Thiers another anylsis of elecrode material around.

(Cole Santos) #17

2 cm/per year accretion rates create the strongest material at 1.2v This growth is 2 dimensional. So to increase rate of growth you simply need a high surface area. A material with 1 cm holeswould only take 6 months, i plan on testing some of the highest surface area materials known to man they may be ready in hours only proper testing will tell.

In terms of the hull Im not sure we need to be water proof. I may simply encase foam or plastic bottles or something. I want to be more like an ice berg and less like a boat.

(.) #19

Seawater dripping 3D print with electrodes and carbon dioxide atmosphere.

(.) #20


I was thinking more like a floating island, therefore different accretion needs.

Regardless, I was thinking of using a layer of biorock to protect and extend the life of a “cheaper” build seastead’s hull. For example, build from marine plywood and epoxy.