The Ultimate DIY Rocks!
- Thread starter JohnL
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Sounds about right to me on the ratio by weight. Don't use volume!
I don't think most people will need the water reducer since we aren't pouring concrete.
Pretty good starting measurements by weight to cement are:
5% micro silica
2% calcium chloride
You can play with percents from there to see if a little more or less works for you.
Carlo
mr.wilson
.Registered Member
Most people use a sand or salt casting to get interesting shapes. Go back about ten pages or so and look at Sunkools? video. You can add more casting media after the first stage and add more on to it for more interesting shapes. The texture can be altered if you use a plastic brush on it after it dries a bit. Screwdrivers and other tools can be used to make holes and contour. A slightly dry mix will help make it easier to hold shapes and give it a rougher texture. The more you mix and handle it, the more water works its' way to the surface, causing a smooth finish. You can spray the rocks with acid after they dry to get a rougher surface.
I use a pre-mixed polymer modified portland mix. It sets in 20 minutes without additional chemicals. I would get similar results at a slightly cheaper cost if I added my own additives such as micro-silica or calcium chloride. Convenience is more important than cost for me at this point in time.
Insane Reefer
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I didn't know Walt had ever replied to the thread, unless he was the guy who posted pictures of the OP's and Barge almost a year ago (I have a vague memory of that) - and I don't remember anything about white rock turning black - not saying it wasn't said, just this first I've heard of it.
What sort of time-frame are you talking about? I got to see some rock I made 3 years ago or so, about 6 months back, when a student who had bought it brought it into the LFS to sell, as he was moving to a new school and didn't know how long it would be before he could get setup again. I'll admit there was some of the dark maroon (almost black) coralline on it, but it certainly wasn't black by any stretch - most was the same you see on any rock, purple and pink. Most of the rock had grown over with things like polyps and the like so there wasn't a lot of "rock" to see, but I've never seen or heard of this.
I would assume that to get buff colors, you are using white cement. Why would adding color to white cement make any difference to the color of later growth?
Neptune,As far as price, $15 for 25# is standard, however if you can't find it locally, assume a $25 shipping charge will be attached to that. So getting it for $20 locally rocks.
I may still want to play with it, but I don't need 25# to play with. If anyone else would be interested in a smaller amount, say 5#, PM me - maybe we can do a group thing - Whoever gets it could sell small amounts via paypal, to others? Just a thought.
Cayars, I agree with pretty much everything you said in your post about rock and filtration, etc - so I don't need to be long winded. I just wanted you to know that those are pretty much my thoughts on it, and will add that I agree with this particular comment most especially:
This is what I've been trying to get across on the thread, but I seem to have failed - you explained it in a way that I hope will allow others to understand why I think the waterproofs are fine for things like walls and plumbing, I don't think they will make good filtration rock...
EDIT: I know that by adding aggregates you can open the rock up some - that water will go through, but water won't be able to pass through the cement itself (the "seeling" effect mentioned) - only the channels made by adding the aggregate, and the channels will provide some places for bacteria, but not like having cement that, in itself, is porous will provide just by its nature, and provides those "dead" pockets that are really nice to have.
And Kurt, Welcome to the thread
Some people just seem to have a knack for it, others, like myself, have to struggle to get nice shapes.
I find that thinking of the piece I want as a multi-story house helps - each level has a different layout, and levels are important to nice rock, IMO.
Once you get something like damp sand in the box, make some divots in it with your fist - fill those with cement. Now carefully cover most of the sand and cement with more damp sand, adding cement to the places that you didn't cover with sand. Build those up a little if you want height, then add a bunch more sand, again leaving places with cement showing. As long as cement touches cement, you should be good to go.
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Insane Reefer
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I think this is where I'm getting hung up - the weight -vs- volume thing.
Our recipes, to make it simple, have always been addressed in "parts" - for example, I use a Chef Boyardee <sp?> Ravioli can - the large one. This is my measure for making rock - if I want more rock, I simply use more cans of my materials. I do know that the can holds about 3# of cement, and eye-balling, would say it holds about 3 cups of cement.
And when you were explaining how to figure out how much calcium would be needed, you said I should start using cups and spoons for measuring.
But you first said I'd need an ounce of calcium, but then had me using a measuring spoon to measure the dry powder.
I am so confused now...
mr.wilson
.Registered Member
I have used a few different water-proof cement mixes in the past, but my current one is quick-setting but not dense enough to hold water. None of the mixes sold as a water-proofing mix are water-proof once you add an aggregate. The aggregate (oyster shell in my case) assures that 50-75% of your rock will be as porous as live rock or better.
The product I use is intended to be used for quick patches of walkways etc. (thus the name Swift Patch). It's more dense than regular portland, due to the internal cure, but it's by no means water-proof. The dense nature of it adds surface area and reduces void space. This makes it superior for denitrification, and less efficient for nitrification.
When I fill the tanks for the first time, the water passes through the cement instantly. I can see it turn dark through the wall of the tank and pool in open pockets as it fills. The cement actually creates a capillary action, so the cement above the waterline turns dark (wet) about an inch above the water line as you fill it.
None of the mixes I have used are any more dense than Caribbean live rock and some South Pacific rock (Tonga branch rock).
This is the only a picture of Fiji and Haiti rock cores in my gallery, but it gives you an idea of what live rock looks like on the inside. Some rocks are much more dense than the stuff I produce. If you were to compare a cross-section of the stuff I use, regular portland, and live rock, you would see little difference. I'll post some better pictures tomorrow.
The product I use is intended to be used for quick patches of walkways etc. (thus the name Swift Patch). It's more dense than regular portland, due to the internal cure, but it's by no means water-proof. The dense nature of it adds surface area and reduces void space. This makes it superior for denitrification, and less efficient for nitrification.
When I fill the tanks for the first time, the water passes through the cement instantly. I can see it turn dark through the wall of the tank and pool in open pockets as it fills. The cement actually creates a capillary action, so the cement above the waterline turns dark (wet) about an inch above the water line as you fill it.
None of the mixes I have used are any more dense than Caribbean live rock and some South Pacific rock (Tonga branch rock).
This is the only a picture of Fiji and Haiti rock cores in my gallery, but it gives you an idea of what live rock looks like on the inside. Some rocks are much more dense than the stuff I produce. If you were to compare a cross-section of the stuff I use, regular portland, and live rock, you would see little difference. I'll post some better pictures tomorrow.
mr.wilson
.Registered Member
Cement and additives really need to be measured by weight for accuracy if you want consistent results. I use a cup to measure by volume and see vast differences in work time and colour with each "identical" batch.
Part of my problem could be that the chemical reaction varies according to temperature, air flow and mixing speed.
I think for most of our use, a rough measurement will get the job done. It's not like building a skyscraper.
Yes thus far you have always talked in volume. A cup of this, a cup of that or 1 part this, one part that. However when you get to adding micro silica or calcium chloride you want to do that based on weight.
So what you do is make your normal mix based on volume but take you total volume of cement and put it on a scale and weigh it. Then add 2% and 5% accordingly based on weight of the other two items.
If you use the same measuring "cup" for each part you should only need to weigh your cement one time and you'll be able to figure out what 2% of calcium chloride looks like. Maybe it would be a shotglass or two. Same with micro silica. Once you figure out the weight you can find something to put it in like a shotglass and work on volume from then on.
It's a one time thing you need to do. I can't give a rough guess either because so many different people use different cements and the weigh different amounts.
Carlo
Insane Reefer
New member
I'm with Cayars with that - if I read his reply correctly, that is.
As I've said, this is a point of contention. Both sides have made their points - at this point, until scientific research is done on this specific rock topic, proving what is more beneficial, can we just agree to disagree and let folks make their own decisions on whether to use water-proof type cements or not?
This is one of those things that can get tempers stirred, and none of us really want that.
As I've said, this is a point of contention. Both sides have made their points - at this point, until scientific research is done on this specific rock topic, proving what is more beneficial, can we just agree to disagree and let folks make their own decisions on whether to use water-proof type cements or not?
This is one of those things that can get tempers stirred, and none of us really want that.
mr.wilson
.Registered Member
Less void space, but still there by all means. You would not be able to tell the difference between fast setting cement and standard portland with the naked eye.
It's just like you see in the pictures I posted, some of those rocks are better for nitrification, while others are better for denitrification, either way, rock work is not considered to be the primary site for pseudomonas. Larger void spaces will allow for a more aerobic environment that is conducive to the growth of nitrobacter (nitrifying bacteria). A tight pore matrix has more surface area.
Of the different media available, ceramic is reported to have the most surface area. Ceramic is much more dense than cement. I'll leave the discussion at that. The topic was discussed in the following thread and included water flow-through rates for rock (which are extremely slow). http://reefcentral.com/forums/showthread.php?s=&threadid=785612&perpage=25&pagenumber=2
I don't understand the instructions given by Reef Balls (are these the same Reef Ball artificial reef structures they sell to rock stars to dump in the ocean?). They advise to use micro-silica and calcium chloride to create fast setting cement, then advise you to cure it for 28 days anyway?
I wanted to post some pics of the rock I made after following this thread. I'm going to probably going to attach them together in the future.
these rocks have been dry curing in the air and have not been put in water to cure yet.
The branching rock is hydralic water stop cement and OS/CC, and the other rocks are portland #1 with sand and OS/CC in varying proportions.
I made some other rocks for my FW tank that I won't discuss here since it would be heresy to discuss the FW tank on the reef board They were water stop cement and CC air cured for one week and cured in water for two weeks.
I also have some questions
can you use any sort of leaves in water while the rock cures to get some color stained on rock or should the leaves be oak? will other leaves be less colorful or should they not be used for some other reason? We have a tree with purple/red tint on the leaves I was wondering what that would do.
I have some grout that I would like to use but I do not know if it will be safe to use. can anyone advise me about the grout in the pic?
one other thing: after MMLR has been in a reef tank for >1 year(assuming it is created to look like natural rock) will it look different from LR that comes from the ocean? I am have read that will will look the same once it is covered in coraline and also have read that it will never look the same as real rock.
thanks
these rocks have been dry curing in the air and have not been put in water to cure yet.
The branching rock is hydralic water stop cement and OS/CC, and the other rocks are portland #1 with sand and OS/CC in varying proportions.
I made some other rocks for my FW tank that I won't discuss here since it would be heresy to discuss the FW tank on the reef board
They were water stop cement and CC air cured for one week and cured in water for two weeks.I also have some questions
can you use any sort of leaves in water while the rock cures to get some color stained on rock or should the leaves be oak? will other leaves be less colorful or should they not be used for some other reason? We have a tree with purple/red tint on the leaves I was wondering what that would do.
I have some grout that I would like to use but I do not know if it will be safe to use. can anyone advise me about the grout in the pic?
one other thing: after MMLR has been in a reef tank for >1 year(assuming it is created to look like natural rock) will it look different from LR that comes from the ocean? I am have read that will will look the same once it is covered in coraline and also have read that it will never look the same as real rock.
thanks
Insane Reefer
New member
Poll Time!
Poll Time!
I was curious about something, and need data, so posted a poll. This is a DIY Rock poll, and is intended to poll those who have made their rock within the last 3 years. Go read, and poll if appropriate
Thanks!
http://reefcentral.com/forums/showthread.php?s=&threadid=1182073
Poll Time!
I was curious about something, and need data, so posted a poll. This is a DIY Rock poll, and is intended to poll those who have made their rock within the last 3 years. Go read, and poll if appropriate
Thanks!
http://reefcentral.com/forums/showthread.php?s=&threadid=1182073
Insane Reefer
New member
MMM, Rhody would be the one to ask about leaves - he is a tree hugger and has played with leaves the most, I think 
FWIW, I'd try the red/purple tree, on at least one piece of rock for a test - pick the leaves and let them dry up first.
I can't see any tree common in the states being poisonous when used this way, but that is just a feeling, not based on anything concrete...
The only difference in the MMLR and Real after a year or so, is that the pieces you finally decide to use will probably be cooler looking than anything you usually see in the LFS's.
I'll let someone else comment on the grout - I'm not a grout fan, I like to control what sand is used, etc. I do see it lists chromium, which I think is considered toxic?
FWIW, I'd try the red/purple tree, on at least one piece of rock for a test - pick the leaves and let them dry up first.
I can't see any tree common in the states being poisonous when used this way, but that is just a feeling, not based on anything concrete...
The only difference in the MMLR and Real after a year or so, is that the pieces you finally decide to use will probably be cooler looking than anything you usually see in the LFS's.
I'll let someone else comment on the grout - I'm not a grout fan, I like to control what sand is used, etc. I do see it lists chromium, which I think is considered toxic?
Insane Reefer
New member
Nice pieces MMM! Especially the branchy ones - I can see the PVC now that you point it out, but other-wise I am not sure I would have noticed...
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