Aragocrete want your opinions\comments

[brianblack]

Well seems everyone talks about making it - techniques - etc but there are no long term 'wow this works great'. I just wanted everyones opinion on Aragocrete good or bad and if anyone has any long term info or a good ratio of live to Aragocrete-let it rip
I read on incident on garf.org about the person who made the rock could not tell it was the one he made after it got the coralline etc on it but lets see what the population at large has to say!

My main reason is that I want to set up my 125 but don't have the capital for lots of live rock - have a 75 with 2 30 gal fuges (1 above 1 below) with about 200 lbs of live rock so could use that to seed etc.

 

[jlehigh]

I'll offer up my experience.

I spent ALLOT of time and a LIL money to make Aragocrete table rocks for my 280gal. It was a fun and frustrating experience when I made the rock, but I ultimately pulled it out of my tank completely.

Corraline will gorw on it, but no where near as well as it does on real rock, this includes the dry rock sold. Ultimately the DIY rock was very dense and heavy and I felt it may have been leaching things into the water column.

I can't say it's bad, or good. Just didnt work for me.

 

[brianblack]

I have read about the leaching also - Aluminum seemed to come up a few times being a byproduct of the cement manuf. process. I am on the fence right now and can't seem to see what side to jump to - Thanks for you reply

 

[MikeS]

The aluminium issue has been debated back and forth...aluminium has been suggested to biocompund and interfere with photosythesis in corals, but some feel that the form of aluminium used in portland cement (aluminium oxide, aka aluminia) does not do this. I'm not a biochemist, I don't know the answer to this, but personally I tend to like to error on the side of caution.

Porosity and density are also an issue with aragocrete...it's real hard to make aragocrete as porous as most live rock, making it generally a less effective media biologically speaking than live rock. Another potential concern is phosphates from the aragonite and crushed shells recommended in most aragocrete recipies I've seen.

If you are looking at it for a FOWLR setup, I'd say it's fine...for a reef, I'd save a few extra paydays and get good live rock...

MikeS

 

[Ed Hahn]

I have had a few friends do argocrete. Their trick was to add plastic to mix.
They also added shavings of coraline from friends tanks. The thing I remember was they had to aireoate rock in water for long time for PH.
One particular friend tore his tank down in a short time after it was set up for 6 monthes.

 

[liveforphysics]

It works, its challengeing to make, but it definately works. Aluminum oxide is bonded in a way that its NEVER going to be able to disolve from any condition present in our aquairums. Aluminum oxide is the same material used on metal grinding wheels, and a variety of other applications where you need something that is basically impervious to damage.

Just so you guys know, the energy released when thermite burns (and creates alumium oxide while stripping the Oxygen from rust to feed its reaction) is the same amount of energy you would need to dump into alumina to get that aluminum back into ion form in the water. Hopefully Boomer can comment on this.

Also, to make your agrocrete spread coraline super quickly, mix in PVC shaveings in the mixture. You can actually make agrocrete with like 3/4ths PVC shaveings and 1/4th crushed coral to add to the cement. Its a very responsible and enviromentally friendly way to do your tank, and you get to design your pieces however you like, which is also very cool. The PVC shaveings grow coraline so rapidly its just nuts, much faster than real rock. Then it rapidly spreads onto the concrete around the shaveings.

Its a lot of work though, dont kid yourself if you think you will be saving any time. Its not the easiest way by anymeans, but it is the most reef friendly method by a long shot.

 

[Krish]

Browse through this link here of one of the members. He's using something similar. Maybe he can give you some feedback as well. HTH

http://www.reeffrontiers.com/forums/showthread.php?t=6928

 

[liveforphysics]

Ed, you must have been typeing while I was, cause you beat me to the plastic thing.

As far as curing goes, salt water is not the best to use for curing it, because it has some properties that delay the complete curing. Best method is to make your agrocrete, then tuck them away in some little nook in a local river or stream to cure. Its not going to effect the river or stream in anyway (unless its a VERY small stream and you are making thousands of pound of rock), and it cures it quickly and completely. If you are paranoid about leeching, leave it in the stream for 2-3months, its like doing a massive continous water change. I would personally never try curing it in buckets and trash cans and things becuase I think thats asking for trouble as far as having it be completely cured and totally leached out.

 

[MikeS]

I'm not a chemist or biochemist, so I really can't say how aluminium vs. aluminium oxide might affect our corals. Maybe it's a more harmless form, maybe it doesn't end up in the water as easily, I don't know. I'd love to see this in the advanced forum and let those more well versed in these type of things take a crack at it...

Aluminium issue aside...you still have 2 major issues to deal with the aragocrete vs live rock issue...porosity and phosphates...

On the porosity...I've seen many ideas to make aragocrete more porous...rock salt, macaroni, plastic shavings, instant rice, seltzer water...the list goes on...I would still imagine it is pretty difficult to make aragocrete as porous as good LR. The true test would be a lb. vs. volume comparison between the two...I have a bin of assorted dried LR (fiji, gulf, marshall, florida aqua)....if anybody has some aragocrete and can measure the lb./volume ratio, I'll do the same...

The second is phosphates...as stated, most aragocrete recipies call for agagonite and shells...both of with are going to be saturated in phosphates...

Most of the BB complaints I've seen about aragocrete tend to center on heavy algae growth...I'm sure there are exceptions, there always are...

MikeS

 

[brianblack]

Using the stream is a good solution to the curing process glad I thought of it.:lol: krish75 the link solution is good but I was under the assumtion - oh no there is that word you know where that leads ... that the more live rock the better for the bio filtration. I do like the heavy rock look with all the nooks and crannies. Spend hours looking for critters.
Thanks for all the replies

 

[dnjan]

I have made aragocrete for specific shapes that I wanted - shapes to set corals on, etc. I incorporate CPVC fittings into my aragocrete, because I have some CPVC pipes imbeded into my sandbed that I can then put the aragocrete onto.

Since these pieces are not very large, I have cured them for a month or so in the tank of a toilet. Flushing changes the water quite regularly.

Concerning aluminum - a non-issue. A real non-issue. If you need proof, you can check out Taylor's "Cement Chemistry" text. Warning - recommeded reading for PhD students only. Any one else I have lent my copy to has fallen asleep. Often.

Concerning phosphates - there will be less phosphates in aragocrete than in live rock, simply because there is less calcium carbonate. Portland cement is not a source of phosphate.

Concerning porosity - aragocrete will have orders of magnitude less useful porosity than live rock. There is nothing you can do to aragocrete to produce a pore system of the correct size range to make it even comparable to the pore system in live rock. So, don't use aragocrete for biological filtration. Use it for supporting corals, for providing interesting shapes and for providing interesting hiding places for fishes, etc.

 

[rainier29]

The stream thing is an awesome idea. Wish I had thought of it when I made mine. I was curing it in a wheelbarrow and trash cans. Six months later it was still not ready.

 

[MikeS]

Concerning aluminum - a non-issue. A real non-issue. If you need proof, you can check out Taylor's "Cement Chemistry" text. Warning - recommeded reading for PhD students only. Any one else I have lent my copy to has fallen asleep. Often.

Thanks Don...if you have a link I'd like to read it...it would be nice to get some clarification on that

Concerning phosphates - there will be less phosphates in aragocrete than in live rock, simply because there is less calcium carbonate. Portland cement is not a source of phosphate.

hmmm....another interesting area to look into...I was always under the impression that dry aragonite sources had a lot more saturated phosphates than LR due to run-off and such...

Concerning porosity - aragocrete will have orders of magnitude less useful porosity than live rock. There is nothing you can do to aragocrete to produce a pore system of the correct size range to make it even comparable to the pore system in live rock. So, don't use aragocrete for biological filtration. Use it for supporting corals, for providing interesting shapes and for providing interesting hiding places for fishes, etc.

Well stated...I agree with that...

MikeS

 

[Ray_D]

Since these pieces are not very large, I have cured them for a month or so in the tank of a toilet. Flushing changes the water quite regularly.

:lol: thats a good one, to bad mine are way to big for that


i make larger peices and use it as base rock under live rock useing the lr as seed to the diy


it works good

 

[liveforphysics]

As far are bacterial surface area goes, once its covered in coraline, its covered in coraline. Live rock or agrocrete, it doesnt make a bit of differnce once its covered in corailine algae, it makes no differnce, it will work for filtration exactly as well as real liverock.

And plastic shaveings in agrocrete covers in coraline very very rapidly. You can have beautiful pink, purple, mint green, red, covered rocks in the shapes you desire for very cheap. Best part of course is that it doesnt require the destruction of natural reefs. But it is a LOT of work, you are arent willing to spend a full weekend up to your elbows in crud, its not for you.

PS Dnjan, that idea about putting PVC tubes for mounts to stack the rocks embedded into the rocks is brilliant! Im going to have to start doing that. I made a really cool Honda symbol rock and toyota symbol rock that I gave to some friends, I also made some tonga branch like rock that was actually japanesse symbols for life, love, and happiness.

 

[wrightme43]

Thats cool about the Toyota symbol. That would be neat.
About the porosity of the aragacrete vs. live rock.
This is what I think on the matter.
Yes the surfaces covered in coraline are covered.
The live rock has a advantage there though, it has boring critters that are constantly chewing new holes in it.
Also the underside of live rock is hugely more porous than concrete. Also even if the crete rock was made with corn flakes and other different sized stuff that would decay out in curing, it just would never have the different pore sizes that live rock has.
I also believe that a signifigant amount of filtration occurs in ours tanks thru sponges and other cryptic and usually unseen items that come in with quality live rock.
I have broken and cut to fit quite a bit of live rock. The stuff inside is amazing.
Burrowing clams from tiny babies to 1" long ones and all in between. Tracks of different things that wind thier way thru the rock, chewing it into dust.
Also is is made from (for lack of the correct term) chambered coral skeletons and layers of coraline, so there is a inherent porosity/ permability as well.
Concrete in my mind is relitivly imperemable (it makes good dams) LOL
Also I dont know of anything other than rock boring urchins who really work thier way into it.
I like the idea of using it for cool shapes, I like the idea of a reef base set on pvc stands built into the rock.
I do think that a reef should be built using live rock. 500,000 reefers with 200lbs each. Is only 50,000 tons of rock. The airstrips built from crushed reef use a whole lot more than that. It is also a renewable resource.
Dynamiting, and prying is wrong. Collecting chunks at the bottom of a reef, or blown off by waves and storms is pretty harmless in my opinion.
Just my thoughts.

 

[dnjan]

Thanks Don...if you have a link I'd like to read it...it would be nice to get some clarification on that
MikeS

Here is a link from Amazon for the Cement Chemistry book:

http://www.amazon.com/gp/product/07...102-0280308-1649747?s=books&v=glance&n=283155

I am not aware of any online sources for the information on the make-up and stability of the compounds in portland cement, as i usually go directly to Taylor's book.

 

[dnjan]

PS Dnjan, that idea about putting PVC tubes for mounts to stack the rocks embedded into the rocks is brilliant! Im going to have to start doing that. I made a really cool Honda symbol rock and toyota symbol rock that I gave to some friends, I also made some tonga branch like rock that was actually japanesse symbols for life, love, and happiness.

When I set my tank up, I glued a number of CPVC fittings to a sheet of plexiglass, which I put on the bottom of the tank. (I wanted the plexi there to protect the bottom, in case i dropped a piece of rock while aquasculpting ) The CPVC fittings were in a fairly regular pattern. the are all coveredwith sand now - some used and some not. But I retained some flexibility with that setup.

luke - that "stand" towards the front, left of my tank with the scrolling tubinaria on it is an aragocrete piece. Inside it is a piece of CPVC pipe. I cut slots in the end of the pipe, and using a propane torch for heat I bent those slots out into kind of a "hand and fingers" shape. Then covered everything with aragocrete.

At one time I had one of the green M. caps on that stand. Worked well, as it held the M cap up off the bottom, but kept it fairly low in the tank. When the M. cap outgrew my tank (at about 12" diameter), jlehigh was kind enough to adopt it. I kept the stand, though ...

I think that somebody going BB could adopt a variation on the CPVC fittings and short aragocrete coral stands system. Just make sure that you hve a good spraybar blowing across the bottom, under the corals, to keep things clear.

 

[jlehigh]

Reading this thread brings back memories I think I read 50 pages on this stuff before I took the cementing plunge..

My Summary
Possible Cons
-PITA to make (the way you want it)
-Less Porous
-Little money savings compared to Dry rock
-Slower corraline growth (with and without plastic)
-Debatable leaching of PO4 not from the cement, but the other texture adding items like crushed oyster shells, maccaroni ect ect
-Lengthy curing

Pros
-Kinda fun
-Custom shapes
-Slight money savings (Maybe)

 

[brianblack]

Thanks Don and everyone for posting here. It is good to have this kind of info all in one thread. I will decide what to do as this project progresses and how much jingle is in the ole pocket. Uncle Sam usually puts his hand on in down to the lint and if there is a hole well you know where his hand will be!:lol: I will prolly use a little of each - live - base - Aragocrete. I am just in the designing stages of what I want to do and I do posses patients and do not have instant reef syndrome - I do try a lot of DIY get your hands dirty a bit see what works and I learn about things better by doing. Reefing is the one hobby or is it life style hmmmmm where everyone is not afraid to talk about their experiences and show the next guy a better way which is great There is always something new to learn! Thanks again all for all the info!!!

Brian