logiktest
Well-known member
Does anyone know if lava ash is reef safe?
Thanks.
Thanks.
Lava ash
- Thread starter logiktest
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logiktest
Well-known member
I would be interested in using it for the production of aragocrete. I know it wieghs very little, to the point of floating. Also it is purple in color.
hmmm...personally, I would avoid it, just to be on the safe side. Portland cement already contains several "iffy" things like fly ash and blast furnace slag. While the nasties in cement may be low enough or in a form that makes them reletively reef safe, I would see no need to up the potential for contamination.
If you want to get a lighter aragocrete, you can try raising the air percentage in the mix by aggresively whipping or mixing the lean concrete (concrete and water only, before any aggregate is added) using an electric mixer and mixxing it until it is frothy. Use just enough water to get it thin enough to mix this way...if you use too much water the lean cement will be too thin to form into shapes.
MikeS
If you want to get a lighter aragocrete, you can try raising the air percentage in the mix by aggresively whipping or mixing the lean concrete (concrete and water only, before any aggregate is added) using an electric mixer and mixxing it until it is frothy. Use just enough water to get it thin enough to mix this way...if you use too much water the lean cement will be too thin to form into shapes.
MikeS
logiktest
Well-known member
I completely agree with you about staying on the safe side of things. The last thing I want is to contaminate my tank or even worse someone else's tank. However, I would think that after the aragocrete has been given a chance to cure, the potential for contamination from the portland (type 1-2) its self is only "iffy" at best, although I am in no position to say so deffinitively.
I like your suggestion about whipping the mixture pre aggregate. Thanks. This draws more questions to mind, but I will save them for a different thread (I once found a thread on RF dedicated to aragocrete composition, sculpting etc., but it was so long the thread split and I cant find the second half now).
As for the lava ash, is there a way I can test for "reef safety"? Perhaps using muratic acid or pickling vinigar to see if the lava ash contains contaminants that will cause the solution to bubble or fizzle? Im not sure if this is an even half way reliable way to test, but I wanted to throw the idea out there. All opinions on this are much appriciated!
I would tend to agree here, cured concrete is pretty resistant to corrosion, the majority of contaminates will likely stay in the aragocrete itself. My worries on aragocrete are time based more than anything. Salt water is a pretty hostile environment, it's pretty corrosive. Over time you may begin to have a bit of degradation of the aragocrete, potentially releasing some undesireable stuff into the water. Having said that, I will say I have never seen anything that points to negative effects of long term use of aragocrete. I think this stuff is pretty safe overall, but I also personally think there is a bit of risk involved in its use. I doubt it would be the primary cause of problems in the reef, but in the long term it may have the potential to compound other problems.
At work I have seen contractors use a form of lean concrete to grout drainage pipes...it's regular portland cement, water, and a foaming agent, which is basically a biodegradeable dishsoap. The ingredients are whipped together in a high RPM pump, the final product has the consistancy of heavy shaving cream. It's pretty amazing stuff, it's very porous, it's much lighter than water, and cures out suprisingly strong. If you could come up with a small amount of a reef safe foaming agent of some sort, this would be the way to go....something to think about.....
Well, if I'm not mistaken, a reaction with vinager or other acid is going to primarily indicate the presence of carbonates and calciums, neither of which are undesireable in the reef tank. I don't think you'd get much of a noticeable reaction with metals, and probably none with silicates, so I don't know that an acid test would tell you much about the lava ash aside from the presence of carbonates and calcium.
MikeS
Boomer
Well-known member
I will just add to what others have said that lava ash can leach crap loads of unwanted elements. Here is an idea of what to expect.
http://volcanoes.usgs.gov/ash/properties.html
http://volcanoes.usgs.gov/ash/properties.html
billaweed
Stumped Irishman
lava and/or lava ash typically contains coppers and other metals. I would avoid puting it in your tank
logiktest
Well-known member
Thank you for the great link.
Well said.
Do you know the name of the product? It does not sound reef safe, but I would like to research it anyway. The wheels in my head are starting to turn...
I can't remember the brand name of it, I'll ask around work and see if anybody remembers. Basically, it's just dishsoap that's also biodegradeable. Perhaps our resident chemist Boomer can think of something that would make a good foaming agent for aragocrete and be safe to use...
The type of flowable fill I've seen being used is called cellular concrete...I'm sure if you did a web search on it you'd come up with several different foaming agent brands and technical data used for creating cellular concrete...
MikeS
acrylic_300
Cleaner Shrimp
If you want your rock to be light add rock salt...it leaches out during the curing process and ends up looking kinda similar to lava rock.
You can also use salt veins across the layers as you clump it and it will melt away into cavities later on.
If you use argonite and salt you don't need to use much concrete to hold it together.
You can also use salt veins across the layers as you clump it and it will melt away into cavities later on.
If you use argonite and salt you don't need to use much concrete to hold it together.
logiktest
Well-known member
Are you referring to layering the salt as you create the sculpture? I have not tried to make veins with salt. Sounds cool. The closest thing that i have tried is when I make arches, I use very large pieces of salt through out the center in order to make the sculpture hollow all the way through. Kind of like a very large macaroni noodle. This saves the sculptures a ton of weight, and gives tiny critters a safe place away from predation.
I use small salt in some of my mixtures when I'm planning to make basic shapes like caves, arches, and tables. When I want to make sculptures more complex with thin walls, I find that too much salt can make the structure very weak. I find that after the salt washes away, many parts of the sculpture that where being held together with the salt end up breaking off and this results in a lot of rock rubble.
Also... Moberly ehh? Do you go to KC or STL for your fish supplies?
One of the comercially-available chemicals for making cellular concrete is called Rheocell. Made by Degusa chemicals (formerly made by Masterbuilders). As mentioned, it is basically a soap (surfactant). When added to cement paste (portland cement plus water), you can then whip the paste with a mixer like whipped cream or egg whites.
Somebody mentioned earlier that portland cemnt contained things like flyash or blast furnace slag. Not very much, and these materials do not cause any problems when mixed in concrete to make aragocrete. In fact, blast furnace slag generally makes concrete more resistant to saltwater.
As it is, aragocrete that is well-cured (4 weeks in regular water) and then kept submerged in saltwater will last longer than the tank itself. The greatest deterioration of concrete in saltwater is in the tidal zone, where the concrete is alternately wet and dry.
