The Ultimate DIY Rocks!

[Rhodophyta]

Originally posted by mr.wilson
The cost of trying the ice idea is certainly cheap and harmless, but I think even standard cement mixes heat up a bit as they set. I've had good success adding textures with compressed air as the rock surface is just starting to set-up. You get a nice moon rock stippling effect if you give it a series of quick blasts.

That sounds neat. My dad worked with concrete. He used brooms and other tools to create texture. He had concrete made with colored rocks and then just after the surface set, would strip it off with a jet point on a garden hose, leaving just the "aggregate" exposed.

I've seen the ice idea mentioned way way back in this thread. It's not my idea, but I missed any reports of how it was tried and the results. Maybe leaving the new rock in a wine cooler or refrigerator would be another approach, if the original one needed revision.

Within limits, like sticking to cheap and harmless. I think using dry ice chunks would be scarey. Sort of like that video where practically a roomful of stryofoam was pushed, vanishing into a large rice bowl of acetone. And then they showed the girl who kept watching closely, passed out on the stairs. Only this video would be chunks of wet rock and dry ice skittering around and chasing the cameraman.

[Insane Reefer]

Problems with ice:
1. Unless large chunks are used, it melts faster than the cement can quick set, thus the "holes" collapse and the "added" water can mess with hydration.
2. Temps of less than 50°F are detrimental to cement cure. Possibly this could be overcome with calcium chloride, however this would cause a rapid rise in the heat generated by the cement, and that would melt the ice even quicker.

Dry ice would actually be better in terms of making rock - the extra Co2 could help with the carbonation process (thus kuring the rock quicker). And as far as I know, the amount of Co2 released by dry ice is harmless to breath (think haunted houses and dry ice fog). Though you'd still have some of the same problems as H2o ice.

Kenjr - you've discovered that in rock kuring, Time = Water. Basically the atmospheric Co2 helped form a shell of calcium carbonate around your rock. Totally safe now, and probably will last a lifetime as it should be more resistant to salt and sulphate attack...

[Rysam]

hey IR, i still have some samples from a looong time ago. both salt only and perlite sand. PM me if you still want them and i'll ship em to you.

[kenjr]

JoelNB, Inkmates & Insane Reefer, Thanks for taking the time to respond to my post , I was really afraid i screwed up my rocks , but i feel a lot better now knowing i didn’t. The rocks i made are for a new setup i will be getting in late July, so ill just keep them in water till then. thanks again Ken

[inkmates]

good luck with the new setup feel free to pm me if you need advice on anything happy reefing

[rguyler]

IR, good to see you back! Hope to see you around more often...

Rysam, maybe it was you who posted about using perlite but I can't recall (getting too old to remember anything ;-). Do you recommend using it? After reading up on it a bit it sounded like the perfect material to reduce density of the DIY rock.

[sikpupy]

Heh heh, dont expect it, she is like Genie on "I dream of Genie". She pops in and pops out at will. You never know when or where she is at any given moment.

[JoelNB]

I'm OK with that. I owe my rockwork to Insane Reefer and I look at it every day and will for years to come

[sikpupy]

I am NOT okay with that. I miss her help and insightful input. She used to be on all the time, now, she barley visits cause we suck and thats sad, or, maybe it is because of my spelling?

[JoelNB]

Curious sense of humour, sikpupy

[goldmaniac]

my live rock is about 2 years old, thought an update is appropriate:

July 2009 FTS showing MMLR:





you can click my Red house for more pics if you would like.

Eric G.

[goldmaniac]

About 90% of the rock in the tank is live rock I made in my garage.

[sikpupy]

Thats pretty good. I think it looks better than mine.







I think I need more cowbell.......er I mean rock!

[SpankythePyro]

So what is the best recipie for this stuff!!!

[big400g]

Hello,

So I do a ton of concrete work and have read through parts of this thread.

Concrete is stronger with less water in the mix, then a long slow cure. Ideally you would water cure the whole time, this will leach some of the lime out of the Concrete and make it look more white. Concrete takes 31 days to reach something like 97% of it’s full cure strength, so it is in this time that it is critical to be nice to your rock, keep it moist and not boil it.

When you mix salt in your mixture the Salt increases hydration and decreases overall strength. Essentially that means that it sets faster, so you have to work fast. Go with a larger salt grain so that you will have large gaps and not have as large a percentage of salt in the cement and thus reducing strength. Also I would pitch the salt in last to make sure that the salt does not melt into my mixture and reduce the strength.

I agree that salt is intriguing as a method to increase porosity, it just should be noted the chemical reaction that it causes and the quality of concrete that is left. This could be why some of you found your rock to crumble.

Perlite is very interesting and can be used to decrease the overall weight of the rock as can pumice. Both should be mixed well into the mix to make sure that you gain the benefits of the protozoan effect. I like a fine grade as opposed to course pebble sized perlite and pumice, they mix in well and do not leave large areas to crack out. Your size of your grain is related to the desired thickness of the rock, so if you want your rock to be thin you want to use things closer to sand. In driveways they use rock because it is 3.5” thick…

I have not yet made my own aragacrete, so I do not yet know the best mixture and it sounds like several people here have done their homework and have great mixtures.

I would try to make the mixture the consistency of clay or peanut butter, put it into your sand molds and press the coral etc into it.

Just thought I would share my 2 cents, and props to everyone on here for a great thread

[SpankythePyro]

Ahh also where can I buy peletized perlite? A;sp how does it even aid the biofiltration/voiding? It doesn't degrade...

And has anyone tried using moisted rice?

[sikpupy]

Originally posted by SpankythePyro
So what is the best recipie for this stuff!!!

Experimentation with the recipies given!

[SpankythePyro]

Will do I'm just trying to find a place that provides perlite!

[tuzeman]

Perlite-r-us

[goldmaniac]

I made three separate batches in Summer 2007 without perlite. my first batch was still so pourous with air that it barely sunk.
I have not tried perlite so I can't say Good/Bad on it but i can tell you that it's not required in the recipe, so if anyone is itching to try it, you can do without.
Unfortunately the recipe I liked the most was a simple whole numbers ratio of 3 intredients like 2:1:1 or 3:2:2 but I forget it exactly, and although i've posted it once or twice on this thread, this DIY thread is TOO HUGE for me to take the time to find while at work.

My biggest challenge was to find WHITE portland cement, but i finally found 90 lb bags of it locally for about $16. I filled up a 5-gallon bucket or two of the stuff just because it was so hard to find. But it makes a big difference, in my opinion, in the look of the tank.

You can't see the difference between grey and white too well in these pictures, but the pics were taken to show the shapes of the pillars and tunnels that are easily made with MMLR:



And here's what the white cement looks like - NEW - in the tank

[goldmaniac]

Originally posted by sikpupy
Thats pretty good. I think it looks better than mine.

Not at all, Sik, just takes time. But thank you. I am glad I got creative with the bridges and tunnels, though.

[goldmaniac]

Found my entry from 2008:

"I like a 1:1:2 ratio of cement: tank sand : Mortons Water Softener salt found at Lowe's or Home Depot, blue bag."

looking back, I'd even reduce the salt ratio to a little under 1. My first batch resulted in a few pieces crumbling over the years.

so I'd go with this ratio: 2:3:2 portland Cement:tank substrate:salt

for "tank substrate", i used old refugium sand that was exhausted, the 'sugar size' stuff. But i did make a batch with larger substrate, crushed coral , and it came out just as good. I think the crushed coral made the rock a little stronger, actually.

hope this helps -

lots of water changes needed for this, and patience. I bought a pack of 50 or 100 pH strips that you just dip in the water for testing. when pH would hit 9.5-10.0, I'd change the water during Kuring after all cement got about a week in my hot garage.

\lots of water changes until pH stabilized at 8.5

[vlepouce]

I was able to get perlite without fertilizer mixed in at a regular garden center here in town. The big box stores only had Miracle grow perlite and that has fertilizer with it.

Good luck

Vic

[SpankythePyro]

I won't be using salt though...so perlite is the answer as it is more cost effective than oyster shells (can't find those), and crushed coral.

Also Gold, how did you get it to form arches like that? What was the actual driping/sculpting process?

[big400g]

As mentioned by a few here, I would not use perlite. It could harbor bacteria if not mixed in right, plus the weight is not really an issue, some weight is good to keep them down and stable. As for the use of refugium sand you will need to thoroughly clean your sand before using it. The detritus will weaken the rocks.

Use the sand for the main mixture of the rocks and the crushed coral to the outside of the rock for looks. A good mixture should be 1:1:1 using larger than rock salt.

I like to use lime in my concrete it makes it more of a clay consistency. I am not sure the effects of the higher lime concentration in our tanks but it could be good.