Artificial Live Rock

[MikeS]

Hi all

I know many reefkeepers out there use artifical live rock, or aragocrete...I wanted to get a bit of discussion going on the subject, and hear from those of you who have used them.

I have seen dozens of different recipies for aragocrete, I have noticed quite a few of them call for Portland Cement. Here is a quote from the PCA (Portland Cement Association)

Portland cement, the basic ingredient of concrete, is a closely controlled chemical combination of calcium, silicon, aluminum, iron and small amounts of other ingredients to which gypsum is added in the final grinding process to regulate the setting time of the concrete. Lime and silica make up about 85% of the mass. Common among the materials used in its manufacture are limestone, shells, and chalk or marl combined with shale, clay, slate or blast furnace slag, silica sand, and iron ore.

The list of main ingredients includes aluminium....

I did some research on the subject of aluminium in the reef tank and I found this from Randy at RC

http://www.advancedaquarist.com/issues/july2003/chem.htm

seems that aluminium isn't so great for the reef tank.... :shock:

I have in the past suggested aragocrete to other reefkeepers and I'm considering it when I upgrade my 55 to a 75 (mainly so I can do a neat aquascaping idea I have) but this is making me reconsider my position on aragocrete.

I'd like to hear from those of you who use aragocrete....

how long have you used it?

what was your recipie?

Have you noticed any negative effects, like unexplained coral death, ect...

photos would also be nice....



Mike

[cich1]

wow i was thinking about trying some for base rock when i start a bigger tank but after reading the list of ingredients i think i may have to place an order with Hirocks

[Khann]

Well this isn't exactly DIY live Rock like agrocrete but I think getting some rock like http://www.customaquatic.com/customaquatic/subsubcategorypage.asp?subcatindexid=ss-sw-rr
this and using it would be a little bit safer and you have no cure time just rinse and drop it in your tank if you have live rock in there the seeding should begin and at around 1 dollar pound it is still better than 5 to 10 dollars a pound that i have seen real live rock go for.

[gman0526]

Personally I have never tried it but sems to me that some people have actually used it succesfully. take for instance the people at GARF.org it seems to me they have to be doing something right.

I think that mainly the difference between it working or contaminating your tank is really gonna be dependent on the amount of cement you use.

Wow Mike! I never thought to read the ingrediants list...and to think they let me build bombs for a living :lol:! Now aint that a scarey thought :eek2: ?

I just went out and got Type II Portland Cement and mixed as per GARF's recipe except for adding the plastic shavings. I have also used recipes calling for oyster shells vice agonite, maccaroni and a number of other items. Thus far all has worked well except the rock salt!

In the pics of my tank here on the forum is quiet a bit of "home made" rock. I havent noticed any ill effects. I did cure the rock for about 6 weeks though changing the water every two days at the most. Dont know what effect if any that may have had on my tank. My coral growth was a bit slow at set up but I attribute this to VHO only lighting as grwoth was explosive (corals) when I went to 400 watt halides. My tank thats posted on the forum is 13 months old.

I primarily use 2 different recipes on a regular basis. One is Crushed Coral (4-5 parts) to Cement (1 part). This makes nice textured rock thats very very porous. It is considerably more expensive though due to the coast of crushed coral. The more commonly used recipe is using 4-5 parts of Crushed Oyster Shell courtesy of the local feed store and cement. This makes a pretty knarly but nice rock thats a bit more dense and cost a "back breaking" 9 cents a pound. No that wasnt a typo...9 cents a pound! Sustituting one part of maccaroni for one part of oyster shell will really open this rock up creating numerous nooks and crannies.

Al;l of this rock will set up a light film of algae on it in bright lights pretty quick. It will be replaced in a few weeks with coralline algae which will grow on the crushed coral or oyster shell first. The rest of the rock will come around soon there after. My best success has been to put this in a 300 gallon vat after curing, bring the calcium level up to 450-500ppm, add some stronium and SeaChems Trace and run this under 2 x twin tube shop lights from Ace Harware that cost 9.00 each and 4(NO) x blue moon bulbs. I usually run the lights from the time I get home from work until I leave for work which is usually 16 hours a day. In about 6 months this is pretty much covered in coralline algae thanks to a couple of chunks of "real" live rock. I have sold this for 4.00 a pound and have had no problem unloading it to fellow reefers or to the LFS if any is left over.

I do a ton of fragging of SPS and to a lesser extent Softies. All of my reef plugs were made using the above recipies and empty styrofoam egg cartons. All coral readily attach and seem to show no difference than ones attached to live rock rubble.

What are the long term effects of using this type of rock over several years, I am really not sure. GARF is using is and have been for quiet sometime, so I am going to assume that it cant be all that bad. Its deffinitely way cheaper, can be molded to specific shapes to fit your needs and make for a very unique tank, at least in my opinion. So I am going to continue to use it. I am even thinking about starting to make the rock for a tank I will be trying to get going that will be at least 240 gallons if not 600 plus, depends on how long my arms are and how deep my pockets are :)

Well thats just my take on this. I am not expert or marine biologist. JHTH's

[jman785]

I use the recipe I posted..that involves salt, for shaping.

But the levels of these metals, are so incredibly low...it doesn't affect anything.

[Whiskey]

Wow nice post MikeJs, and Imaexpat2, I do use this stuff as well, although I have only just put it in the tank I really like the idea. It would have taken me years to save the money to have this much "real" live rock. Now I can give my fish a much larger tank and start to add coral (something I have always wanted to do). I used 1 part concreate to 6 parts crushed coral (got on sale for $4 per bag) and a moist sand mold to form a shape.

I would like to know if anyone has more info on this practice however; this post does have me a little worried.

Thanks,
Whiskey

Well I have used some of this rock for about 18 months now, although most of the rock is only about 13-14 months old. I am going to stay the course...pending any earth shattering developments. Thats just my take on this, although it does raise the eye brows a bit to be sure.

Since I am kinda in limbo for about the next 90 days pending a job offer I got here locally meaning no 2400 mile move in the near future, think I am going to make some more this coming week end. I got some time to kill. Probably about 40-60 lbs of "rock rubble" for coral frags and another 50 lbs or so hand sized pieces for growing out some Zoanthids and Starburst Polyps.

It would be kinda nice to hear some more about this from some other reefers though. I have followed this type topic on several other forums and there doesnt seem to be a whole lot of people doing this and there doesnt seem to be any more ideas floating around that havent already been discussed here.

[creepingdeath086]

no matter what size or type of cement used, it has to be cured for long periods of time, i use a few cement rocks in a 2.5 gal bow, freshwater, and had no problems....what ever you do make sure they are cured

[MikeS]

I use the recipe I posted..that involves salt, for shaping.

But the levels of these metals, are so incredibly low...it doesn't affect anything.

Aluminium seems to be somewhat toxic in small amounts....many reefkeepers are getting away form phoshate reducing filter media that are aluminium based...

My main concern with this would be long term leeching into the tank...that's why I'd like to hear how long you reefkeepers who use them have had them in your tank.....

Mike

[FishinInTheDark]

Mike,

What do you mean by "long term leeching into the tank"? If the tiny amounts of aluminum leeched out of the rock, you would control it with your water changes. I don't think it would adhere to glass, and the minute amounts would be ingested and expelled by corals and fish without damage. Again, water changes (or skimmate) would remove it. We worry about putting copper into our tanks because the live rock can absorb it, but if the aluminum is already in the rock in , then I'd think the rock would just get safer over time. Am I making sense, or just rambling?

BTW, I drove past your town over the holiday. I sure wanted to go to the Sunrise fish store on the way home, but we were all too cranky to even attempt such a thing. . .

TC,

Conni

[MikeS]

well....if there is a constant leeching into the tank it could be problematic, like some have experienced when using aluminium based phosphate reducers long term.

Also, I'm not sure how difficult aluminium is to remove from the tank....

Mike

[Sergio Henrique]

Yes, I realy liked this rock, and I am think to do it but what now about this aluminium ? Also I'm want to put a small amont of this rock, mixing with dead live rocks e real live rocks.

[MikeS]

Don't get me wrong, the purpose of this thread is not to scare anybody into not using aragocrete or remove it from your tank...I'm just trying to get some input from those who have used it or currently use it, to see if they have had unexplained problems with coral health in their tanks.

I've been checking into it a bit more on other sites, it seems aluminium is generally recognized as undesireable in the reef tank, but I can't seem to find any information linking the use of aragocrete to unexplained coral deaths/ poor health problems. I have however seen several posts from people blaming aragocrete on increased algae problems, but who knows if there is any real correlation there or not.

Mike

[mojoreef]

I think on of the main problems with concrete rock is the lack of pourious. With thslurry that is formed through out you really dont get the bacterial surfaces you need for filtration. As per alluminum, yes it can be a problem, specially in regards to soft corals.

Mike

[jman785]

I have to go with Conni on this as I do believe that the Aluminum would have to be kept in the water column, therefore it is replaced by new water, every time you do a water change. I don't see this being a problem, as long as they aren't an old school deep sand bed fan, or a plenum dude, as I know a lot of they, who don't change their water...and haven't in months/years....They have wonderful tanks though, but I do see this becoming a problem over a period of time if the water isn't changed.

[Sergio Henrique]

I friend of mine told me there is no problem to use this live rock, because the cement do not make reaction with saltwater, and cause this theres is no problem about the aluminium.

This can be truth ?

thanks

[MikeS]

Well...any amount of the aluminium coming in contact with the salt water will corrode. If aluminium is leeching into the tank, sure, a water change will remove whatever aluminium is in the water that is actually removed from the tank. But....nobody changes ALL their water at once...so there will still be aluminium in the tank water, and the aragocrete would still be releasing it into the tank...

After doing some more reading, it seems that aluminium is a somewhat difficult element to process by many living orgainisims. If the corals in the tank are exposed to aluminium on a long term basis, there is a good potential for it to build up in the tissues until it reaches a toxic level....this would be my main concern....

Mike

You make some good arguments to be sure Mike. I wouldnt have gave it a passing thought if you hadnt brought it up. It may indeed be a very real concern.

I am hesitant to get too excited about it though. GARF has been using this for a couple of years at least that I know of. In some of thier tanks this is the only rock in it. They seem to be quiet the eye candy too for the most part. Thier success is kinda hard to ignore. It is possible that none of these tanks has been set up long enough to really show long term effects.

Tomorrow if I get the time I might drop Leroy a line and see if they have some insight on this that the rest of us dont have. I am kinda curious if this has been a consideration since they advocate this to such an extent.

[mojoreef]

The Main problem with metals such as alluminum is that they get taken in my the mucus membrane of the coral itself, then the metal begins to oxidize and takes the corals mucus with it. Once that occurs the coral becomes less able to fight off UV damage and is very susceptable to bacterial infection. Water changes my get some but the vast majority of metals are taken in by biologicals as they are to a point a nutrient.


Mike

[MikeS]

Water changes my get some but the vast majority of metals are taken in by biologicals as they are to a point a nutrient.

That's what I'm worried about...even if the aluminium leeching into the tank is minor and the reefkeeper is "keeping up" with water changes, I'd be afraid that the aluminium would be building up in the corals....

Mike

Well I e-mailed Leroy, but havent herd back from them yet. I would imagine they are kinda busy and possible "wrapped around the axial" at the moment. If they respond back though, I will post thier reply.

[29NaNo_ReEf]

wouldnt the curing period eliminate these harmful ingredienst in the cement?

Mike

[jman785]

Not necessarily.

Mike, I'm starting to see your POV.

Now you've caught my interest now.

Time to do some tests.

[MikeS]

wouldnt the curing period eliminate these harmful ingredienst in the cement?

No...the process of curing will not reduce the amount of alumnium. I'll look in one of my ACI manuals at work this week, maybe there will be some information in there on why aluminium is used and how it affects the curing process.

Mike

[gman0526]

Mike, a little off subject. In the May 2004 issue of Reefkeeping there is an interesting article on the qualities of Live rock as a biological filter..

http://reefkeeping.com/issues/2004-05

Thought it might interesting for everybody to read since it brings up a lot of points.

[FishinInTheDark]

Interesting, Gman.

I'm a little confused as to how so many people succeed with the Berlin method if only the highest quality live rock will function properly as the biological filter. And then Berliners w/abundant corals would be even less successful. . .

But, everything he says makes good sense.

Thanks for piquing my curiosity!

Conni

[MikeS]

Interesting....I had read that a few months ago...

The one assumption of his I have a problem with is that animals living on the LR are absolutely essential for water diffusion through the rock. I just don't think that is the case in a tank with ample circulation and LR that is reasonably porous...Also, osmotic pressures will move water through the LR IMO.....

Mike

[gman0526]

The way I see it... is really all dependent on how porous the LR really is, regardless of how many "macroorganisms" actually live within the "pores" in the rock.

As a matter of fact wouldn't it make more sense that the presence of these organisms within the rock actually disrupt the growth of bateria???