DIY Rock

[Mac1]

3 Thoughts:
- Contemplating making my own Live Rock for my new tank, instead of shelling out $1K for transhipped Tonga Branch. However therein lies my problem. I've no qualms about doing the DIY thing, can wait 2 months for it to cure... But really wanted "Tonga Branch Rock" for my display. Was toying w/ the idea of using 1/4-1/2" PVC and fittings to create cores to form the concrete around... but don't know if that will give me the long, branching, thin shapes I'm looking for. Anyone every try it?
- Did some digging (ozreef.org, here, RC, Thiel site), but couldn't find any tricks on making the rock light and porous (they all just say to make it a 'dry' mix as opposed to 'wet'). Anyone try adding Macaroni or other organic item to their LR mixture? Does the stuff dissolve/disappear during the cure?
- I also hope to pre-form holes for coral plugs if I decide to go this route - any problems w/ just jamming some 1/2" Dowel pieces into the rock as it's curing? I figure a Screwdriver can remove it easily enough after it's cured.
Thanks for the input.

- Mac

 

[fishfarmer]

Never made rock myself, but it sounds like adding a "core" would be the way to go for making branching rock. I wonder if using some form of bendable plastic would work or hot glue sticks with the ends melted together.

 

[sschafer]

You can try flexible PVC. I've got some 3/4" that is pretty flexible. The larger the diameter the less flex to the matterial. Mac you can get this stuff at Debbie Supply. That was the only place I found it though I did not do an extensive search in Rochester.

-Steve

Never made rock myself, but it sounds like adding a "core" would be the way to go for making branching rock. I wonder if using some form of bendable plastic would work or hot glue sticks with the ends melted together.

 

[Mac1]

I wasn't even thinking of anything that complicated... Was just going to use some T's, Wye's and 45's, to make branches a foot or two long, have little stubby side shoots, like the real stuff does. I just figured it would help shaping things a little better, as oppsed to just laying it in a sand mold, and also help the weight (not to mention, give the bug's a cool place to swim and hide!) Might even get really tricky, and leave some ends open, and just connect them like tinker-toy's!

- Mac

 

[texasreefer]

W/ the pvc you can heat it up w/ a heat gun like you use to strip paint and you can bend it into any shape you want. Once it cools it will maintain the shape you bent it in.

 

[buff1]

I made the rocks in my 20 gallon tank using the "aragocrete" method on the GARF website. I will honestly say that my results have been mixed. The upside is that you can make some really cool custom shapes. I made tubes that my fish love to hang out in for example. You can make platforms that can hold whatever livstock you want. I even thought about making a "sandbox" that would be sort of a bowl or tray that sits up at mid depth of the tank but holds sand in it. You could sit a couple of clams in the sand. There are, however, a few downsides. I experimented with putting pasta in the mix and did not have great results. The pieces had a harder time staying together if I put more than a tiny amount in. Another downside is that when you begin with a sterile rock, bad stuff can really outcompete the good stuff. After more than a year, the rocks look kind of natural, but still have very little coralline on them while other surfaces in the tank have plenty of coralline. Turf algae simply took over the surface and the corralline could never quite get hold. If I were you I would think of the artificial rocks as primarily base rock and still purchase some nice Tonga or Fiji rock to cover the visible portions of the reef.

 

[oimate84]

Insted of all the trouble to make the rocks, why not just get a bunch of base rock for less then half the price of live rock and seed it with some Live rock. Check out www.hirocks.com for cheap hawiaan base rock...

 

[Mac1]

I thought of doing that, get one box of rock and use it for starter rock, or crush a bunch up and use it for texture... I've seen some interesting idea's mixing reef rock in with home made pieces when making them.

- Mac

 

[Mac1]

Got tired of wondering.
I had run out of work early and found a Feed Supply place 20 minutes away, got lucky, they had a 10 Lb. bag of crushed oyster shells right there on the shelf.
$2.30

Stop at Home Depot, Bag of SouthDown Sand, bag of Portland cement mix.
$8.65 (god this crap's cheap!)

It cost me 11 bucks, and by tomorrow, I'll know if this stuffis any good
Took me about half an hour, including clean up and a cigarette break.
Not bad, even tho the wife's bitching... I mentioned how it might save me money on the new tank, and 15 minutes later when I passed by again, she asked how things were going

- Mac

 

[beerbaron]

yeah thats the way things usually work. good luck. have you ever worked with concrete before? get ready for some dry hands. where crappy clothing. especially shoes. concrete drys stuff out quick.
HTH

 

[aversion]

Here's a crazy idea...Could you maybe still make the rock in a sandbox, but use use twisted/rolled/scrunched up wax paper to form the hollows in the rock?? Just make sure you leave some paper hanging out the bottom so you can pull it out when the mix hardens.
This way it would be more customisable (and cheaper) than the pvc and keep the rocks light.
Hows about replacing some of the sand/oyster shell with crushed marble up to 1/4" size to give a chunkier look.
Just a couple of ideas

 

[teevee]

how about using potters clay? it would be a million times easier to work with. however i'm assuming it's toxic or something, because someone else must have though of this before. i myself do have access to it and a kiln...

 

[craw]

Stop at Home Depot, Bag of SouthDown Sand, bag of Portland cement mix.
$8.65 (god this crap's cheap!)
- Mac

Any brand in particular?

 

[Anonymous]

Back to the original post, a question: Have you ever worked with Tonga branch rock? It looks awesome and looks like it would be great rock to have, but in reality it's a b!tch. It's heavy and dense, meaning it won't support a great deal of bacterial colonization, and it's a pain in the butt to stack--it won't hold against itself, you can't make any decent shelving with it, etc.

Figi and Marshall (my personal favorite) are much better.

 

[craw]

Mac, what was your mixing ratio?

 

[AnnArborBuck]

ScubaDude has made some tonga looking DIY rock. Here is a link.

Tongra Branch Rock

I have made some tonga branch rock using a mortar bag. It looks like a large cake decorating thingie, i found it in the cement aisle at HD. I just filled the bag with the mixture and squeezed out long branches. What you have to do is make one branch and then cover that branch (minus the base) with more oyster shell. Then make another couple of branches. Cover those (except for base) and repeat. These are pretty fragile so be carefull handling them, give them extra time to dry and harden.

There is a ton of information on making rock (including tonga) on the [url =http://www.garf.org]Garf Website[/url].

Good luck.

 

[Mac1]

Wow! Thanks for all the idea's.

AnnArborBuck: thanks for the link. That's the kinda stuff I was hoping to be able to make. Guess I have to get better at creating my molds.

Craw: I did just like the directions on the GARF pages says, about 5:1, however found it too runny, didn't look like there was enough cement, so I added about 0.5 scoops more. As for the Portland Cement, quickcrete was what they carried, that's what I bought .


Sharkky: I've got about 1/3 Tonga now, and 2/3 fiji (couple pieces of Florida rock in there too), and I like the Tonga a lot better. I'll admit it can be a bear to stack just right, but you can get the hang of it. I'll be able to leave my current tank running for a couple of months also, while I futz w/ the LR and get everything just so... Part of the plan was to spend lots of time getting the rock-stack just right.

teevee: saw a few alternate materials listed in some other DIY pages I found (perlite, various powdered rocks, plastics, etc.) but never mention of the potter's clay. I've heard clay's can contain some heavy metals, and are generally advised against.

LOL! Thanks for the tip Baron, wish'ed I'd thought of that before going to home depot in my leather jacket...

Anyways, I got a look at the rock today (22 hours cure time, close enough)... turned out OK.. I definitely need to get better at building my molds (might try and make some out of plastic). That mortar-injection thinggy sounds neat (AnnArborBuck), I might try that. My only complaint is that it seems awful brittle still. Just in handling it while trying to rinse some of the excess sand off the rock, a couple of things broke here and there. Nothing big, I didn't lose any of the branches I tried making, but still.. wouldn't hold up long in the tank! I'm wondering if this stuff will harden more and cure better once it's been soaking in water for 6 weeks? I've got it sitting in a trash can filled w/ the waste water from my RO, as I can cycle that rather quickly. Might try some in the toilet tank if I can sneak it past the wife and upstairs ..

- Mac

 

[CAT]

I tried making the same mix for my last tank - Took a really long time to cure. Before you use it, let it sit in a bucket of fresh water for a couple of days and test the pH. Six weeks wasn't long enough for me and I was changing the water every couple of days.

Good luck