Mineral Accretion technique

[iantoh]

hi there everyone, i saw a documentary on mineral accretion experiments in mexico on discovery channel about half a year ago, and recently went through a website on the subject again and wanted to ask everyone what they thought about it, and if the idea has potential to be applied to our reef tanks.

mineral accretion, in short, is the placement of a solid steel frame structure into the ocean, with a low voltage electrical current connected to the steel frame. this electrical current causes calcium carbonate to form and entirely encrust and cover the steel structure within weeks, making it waterproof and rustproof. coral fragments that are then attached to this steel structure grow at an accelerated rate. this method is being used to restore coral reefs all around the world now, from thailand and mexico to papua new guinea.

this is the website:

http://globalcoral.org/Solution%20for%20Co...0in%20Peril.htm

i was thinking that, because we have calcium reactors nowadays, that maybe this method of increasing coral growth might be experiemented on in our captive tanks. what do you think? any thoughts?

cheers,

ian

ps: singapore has a greater species count of corals than malaysia, but the majority of our coral reefs have been destroyed by sedimentation and land reclamation. perhaps our reefs can be restored this way?

[Dazza]

interesting piece of info...

[klim]

Saw that documentary...they wanted to restore the reef, so they tried that method and within months, they discovered corals start growing and fishes came back.

Maybe can try that method by putting a small current rod into the tank and see whether things start growing...

[Lester]

Good idea... but dunno if it will work out in captive tank.. hmmm it seems like it only works fot SPS.. i am right? ( do correct me if i am wrong .)

[Lester]

i was reading thru the article..

it stated frame, often made from construction grade rebar or wire mesh.. it will leak copper in the water???

one more point..

Then a low voltage direct current is applied using an anode (power sources can include chargers, windmills, solar panels or tidal current generators). This initiates an electrolytic reaction causing mineral crystals naturally found in seawater, mainly calcium carbonate and magnesium hydroxide, to grow on the structure.

does this means the corals consumes the minerals both from the frame they are stick to and the surrounding waters????

just wondering ...

cheers:

[hotlemond]

one could experiment it in a holding tank, without fishes. But am quite concern of the straying current around the equipments. I do believe MH/T5, Ca R, pumps had to be running there too during the "electrocution" period rite?

[Lester]

one could experiment it in a holding tank, without fishes. But am quite concern of the straying current around the equipments. I do believe MH/T5, Ca R, pumps had to be running there too during the "electrocution" period rite?

Hi bro,

hmmm ... IMO , i think if this was to done in a captive tank.. everything will be as per normal which means.. include CR, return pump, skimmer, MH/T5, minerals to be added, equipments etc etc to be running.. but addition of steel bar ( frame) and current attacted to the frame..

will as i was saying.. dunno if the steel frame will leak any harmful minerals liek copper back to the water ...

hmmmmmmmmmmm

[hotlemond]

Hi bro,

hmmm ... IMO , i think if this was to done in a captive tank.. everything will be as per normal which means.. include CR, return pump, skimmer, MH/T5, minerals to be added, equipments etc etc to be running.. but addition of steel bar ( frame) and current attacted to the frame..

will as i was saying.. dunno if the steel frame will leak any harmful minerals liek copper back to the water ...

hmmmmmmmmmmm

har..., won't our fishes get a hair raising experience??

[Lester]

hi bro hotlemond ....

hehe from the article it stated

" In practice, a low voltage direct current is fed to the reef via cables. The structure acts as a cathode. A special inert material is used as the anode to complete the electrical circuit. The low power is completely safe for swimmers and marine life."

dun reali think the fish will feels the electric.. if not .. we can have BBQ fish

hehe btw when is the raid on acidjazz and reefer han going to carry out ???

cheers

[iantoh]

hi everyone,

i think the voltage wont really be felt by the fishes and all. i mean, most of the powerheads and electrical appliances that we use on our tanks occasionally leak some stray current too, and theres little noticeable effect.

as for the leeching of toxic metals into the water column, i think thats not an issue because the structure is meant to be made entirely of steel. furthermore, as the article details, the steel is entirely waterproof and rustproof within 3 wks time due to the calcium carbonate encrustations that totally cover the structure, so i doubt any metals like copper will leech out, because if they are even present, they'll be locked in. still, i guess we wont really now till we've tried it out. i think the method works for all stony corals, that is, corals with calcium carbonate skeletons. ive seen some of the photos showing gonios and lps and even soft corals. it probably doesnt affect non calcium building corals.

and as for how it aids growth, this is a paragraph from http://www.reefhq.com.au/bts/electro.html, basically saying that the attraction of free calcium ions towards the electrical current makes the mineral easier for the coral to obtain and hence grow.

"when corals grow in the wild, they extract minerals from seawater and use them to build into their limestone skeleton. After the discovery of electro mineral accretion, other scientists came up with the idea of attaching pieces of coral to the mesh (the cathode). They reasoned that if they put the corals on that surface, the calcium carbonate needed for the growth of their limestone skeleton would be attracted to the cathode and be much easier for the coral to obtain. The theoretical result would be that corals that are stimulated by an electric current grow faster than corals without stimulation. Evidence even exists that corals that are grown by the EMA method are less susceptible to stress and disease. These observations could prove important in future reef restoration activities."

i think if its tried with a full sps tank, the ca reactor might find it hard to keep up with the ca needs though. what do you think?

[hotlemond]

dun reali think the fish will feels the electric.. if not .. we can have BBQ fish

hehe btw when is the raid on acidjazz and reefer han going to carry out ???

cheers

oh ya...

almost forgotton about that.

Thanks Ian,

but we have found another means of cooking up a delicious stingray with sambal.

just kidding...

[minsmarine]

Would that be temperature play a bit ? I am just gussing. As we know CaHCO3 will raise when temp is raise.

[Achilles Tang]

folks, you may try this in your reef tank but you will probably have nothing but coralline algae growing on it.

Our tanks rarely has coral spawns that could result in such settlement.

Nice thoughts though....

[Alentino]

How about transplanting small frags unto the steel and see if it really has accelerated growth?

[Lester]

hi everyone,

i think the voltage wont really be felt by the fishes and all. i mean, most of the powerheads and electrical appliances that we use on our tanks occasionally leak some stray current too, and theres little noticeable effect.

as for the leeching of toxic metals into the water column, i think thats not an issue because the structure is meant to be made entirely of steel. furthermore, as the article details, the steel is entirely waterproof and rustproof within 3 wks time due to the calcium carbonate encrustations that totally cover the structure, so i doubt any metals like copper will leech out, because if they are even present, they'll be locked in. still, i guess we wont really now till we've tried it out. i think the method works for all stony corals, that is, corals with calcium carbonate skeletons. ive seen some of the photos showing gonios and lps and even soft corals. it probably doesnt affect non calcium building corals.

and as for how it aids growth, this is a paragraph from http://www.reefhq.com.au/bts/electro.html, basically saying that the attraction of free calcium ions towards the electrical current makes the mineral easier for the coral to obtain and hence grow.

"when corals grow in the wild, they extract minerals from seawater and use them to build into their limestone skeleton. After the discovery of electro mineral accretion, other scientists came up with the idea of attaching pieces of coral to the mesh (the cathode). They reasoned that if they put the corals on that surface, the calcium carbonate needed for the growth of their limestone skeleton would be attracted to the cathode and be much easier for the coral to obtain. The theoretical result would be that corals that are stimulated by an electric current grow faster than corals without stimulation. Evidence even exists that corals that are grown by the EMA method are less susceptible to stress and disease. These observations could prove important in future reef restoration activities."

i think if its tried with a full sps tank, the ca reactor might find it hard to keep up with the ca needs though. what do you think?

good piece of info brother

[blueheaven]

How about transplanting small frags unto the steel and see if it really has accelerated growth?

I think it's not the steel but more on the minerals that forms there due to the electrolytic reaction. But I am still curious as to how these minerals can be taken in by the corals

Most likely is that the minerals precipitate on the steel cathode and stay there. It's just like sticking frags onto coralline algae as they to contain calcium carbonate and even an increased level of magnesium

I think it is a natural process as I do know of some reefs which was damaged and eventually grow back in half a year. Unless you are saying that you can pass a current through a frag so that the calcium carbonate precipitates on it.

But anyone "gung ho" enough to try it in captive reefs, I think many would be interested to track it's progress

[iantoh]

hi there blueheaven and fellow bros, just some more thoughts...

i think the primary reason why the electrolysis affects the rate of coral growth is because it makes calcium more readily available to the corals placed on the electrified steel structure as compared to without the electrification. corals obtain calcium through the water column by a process of ion-exchange in a fliud layer that exists within the area of coral tissue that is closest to the coral's skeleton- the extracytoplasmic calcifying fluid or ECF layer. now due to the mechanisms occuring within this layer (see linked article), where calcium is fused with carbonate to form aragonite that is the final skeletal material of corals, the higher the level of calcium in the region surrounding the ECF, the greater the ability of the coral to absorb and use calcium, and hence, greater rates of growth. at least, this is the rationale of mineral accretion.

the electrification of the steel structure causes calcium ions, and other minerals like strontium, to be attracted and drawn towards the structure. this then provides elevated calcium levels in the water area surrounding the corals, thereby facilitating increased growth. thats the rationale for maintaining levels of calcium at higher levels than which occurs in NSW, because at 500ppm, calcium is more readily obtained and used by corals than if it were at 400, or 300ppm. and NSW's calcium levels can be as low as 200-280ppm.

well, once i can afford the costs of starting another system, that is, once i start work, i'll give this thing a try ya. promise. just gotta get myself employed first. hahha. to those that might be interested, heres an article that explains the ECF thing and how corals obtain and use calcium. its quite scientific but really enlightening. http://www.advancedaquarist.com/issues/apr2002/chem.htm

i learned alot from that article, and hope it makes good reading for you too ya.

cheers,

ian

[blueheaven]

But when the ions are reduced at the cathode, won't it remain there and not leech out? Even if the ions are "leeched out", i think they will just get reduced again at the cathode. And when calcium carbonate forms a layer on it, will it still be effective?

And thanks Ian for the article, it is a good read

[iantoh]

hi there blueheaven,

i'm not sure about the ions leeching out from the cathode. also, i'm not too sure about the exact ion exchange formulas that take place, but from what i know, the electrified steel structure basically just serves to attract calcium and other mineral ions towards it by means of a charged ion field. this draws all the ions from the surrounding areas towards it. and as the corals are attached to the steel structure, these corals then benefit from having elevated ca and st levels in the immediate vicinity around it, enabling it to grow quicker.

well, something like that i think. i flipped through some asian aquarium magazine at the magazine stand at Ikea today too, and hey, theyre advertising for people who want to adopt a piece of artificial reef in singapore. around pulau semangkau and kusu. cool huh? i'm gonna try to find out more about that. if anyone knows more about this, pls do share with all of us ya.

cheers,

ian

[blueheaven]

Oh you mean the adopt a reef activity?

I had adopted my own concrete structure

Wonder what sort of frags are they going to stick on it

[iantoh]

hey cool! hahah. maybe you could ask if you can personally tend your reef structure, place some frags from your tank.

[decentkid]

ok..this is what i understand..how i accurate i dunno..after all i am a student...but hope it helps

firstly, lets look at the main ions which we are concerned about: Ca 2+, Na+, Mg2+, H+, Cl- and OH-

from the above, we can tell that Ca 2+, Na+, Mg 2+ and H+ will be reduced at the cathode and Cl- and OH- will get oxidised at the anode

however for the ions at both the cathode and the anode have different ease discharged depending on their standard electrode potential

for those at the cathode, the higher the standard electrode potential, the easier they are discharged

Ca 2+ + 2e -> Ca -2.87V

Na+ + e -> Na -2.71V

Mg2+ + 2e -> Mg -2.38V

H+ +e -> 1/2 H2 0.00V

for those at the anode are the same

2Cl- -> Cl2 + 2e -1.36V

4OH- -> O2 + 2 H2O + 4e -0.40V

from here..u can see that H+ is favoured to be reduced at the cathode and OH- easier to be oxidised at the anode...hence the oxygen and hydrogen as mentioned in the article...which also means the other ions wont get discharged

as water within the region gets lesser, concentration of ions around starts to increase, hence equilibrium shifts and this results in the increase in the standard electrode potential of chloride ions and hence it is easier for chloride ions to be oxidised and hence the presence of chlorine gas at the anode

as i mentioned that the ion concentration around the steel increases, using bro iantoh's example, calcium ion concentration increases from 300 ppm to 500ppm

calcium ions combine with carbonate ions to form calcium carbonate which makes up the lime stone via the formula:

Ca2+ + CO3 2- => CaCO3

with an increase in concentration of calcium ions, equilibrium shifts to the right, which means easier for CaCO3 to form, hence speeding up calcification

hope this help u all to understand...well..in any case...thats how i understand

like i said, how accurate i dunno, all these are what i learnt in school, still a student, but still hope it helps, and hope it isnt too difficult to understand

just my 2 cents

[iantoh]

wow. hi there decentkid. good explanation! thanks.

[Lester]

wa... this is one chim thread for me but dunno why . it reali drew my attention to it ...

keep it coming..

great work guys

cheers

[decentkid]

ok..this is what i understand..how i accurate i dunno..after all i am a student...but hope it helps

firstly, lets look at the main ions which we are concerned about: Ca 2+, Na+, Mg2+, H+, Cl- and OH-

from the above, we can tell that Ca 2+, Na+, Mg 2+ and H+ will be reduced at the cathode and Cl- and OH- will get oxidised at the anode

however for the ions at both the cathode and the anode have different ease discharged depending on their standard electrode potential

for those at the cathode, the higher the standard electrode potential, the easier they are discharged

Ca 2+  + 2e -> Ca     -2.87V

Na+  + e -> Na        -2.71V

Mg2+  + 2e -> Mg      -2.38V

H+  +e -> 1/2 H2          0.00V

for those at the anode are the same

2Cl-  -> Cl2 + 2e    -1.36V

4OH-  -> O2 + 2 H2O  + 4e   -0.40V

from here..u can see that H+ is favoured to be reduced at the cathode and OH- easier to be oxidised at the anode...hence the oxygen and hydrogen as mentioned in the article...which also means the other ions wont get discharged

as water within the region gets lesser, concentration of ions around starts to increase, hence equilibrium shifts and this results in the increase in the standard electrode potential of chloride ions and hence it is easier for chloride ions to be oxidised and hence the presence of chlorine gas at the anode

as i mentioned that the ion concentration around the steel increases, using bro iantoh's example, calcium ion concentration increases from 300 ppm to 500ppm

calcium ions combine with carbonate ions to form calcium carbonate which makes up the lime stone via the formula:

Ca2+  + CO3 2- =>  CaCO3

with an increase in concentration of calcium ions, equilibrium shifts to the right, which means easier for CaCO3 to form, hence speeding up calcification

hope this help u all to understand...well..in any case...thats how i understand

like i said, how accurate i dunno, all these are what i learnt in school, still a student, but still hope it helps, and hope it isnt too difficult to understand   

just my 2 cents       

the standard electrode potentials i quoted might be a little confusing, so i bracket them up in here so easier for u guys to compare

for those at the cathode, the higher the standard electrode potential, the easier they are discharged

Ca 2+ + 2e -> Ca (-2.87V)

Na+ + e -> Na (-2.71V)

Mg2+ + 2e -> Mg (-2.38V)

H+ +e -> 1/2 H2 (0.00V)

for those at the anode are the same

2Cl- -> Cl2 + 2e (-1.36V)

4OH- -> O2 + 2 H2O + 4e (-0.40V)

thanks bro iantoh, hope it helped u to understand

bro lester, tried to explain in the simpliest way...but dunno how to make it more simplier...sorry if too chim