DIY rock who`s made it and what`s your recipe?

it's really not that hard to make, i have noticed if theres not enough portland in the mix the rocks will slowly start falling apart. I think we used like a 3 to 1 mix salt to portland, if i were you i'd wait til you decide for sure on a tank size and make a mock up tank out of ply wood and then build a pvc rack and build the rock around it, that would help keep the flow decent under the rock and give your fish more area to swim. Let me know when your gunna make it and i'll bring you my mixing tubs.

 

If you decide not to make your rock check out http://www.marcorocks.com. I purchased 50lbs and it is excellent quality. Below are pics of what it first looked like in my 90g and what it looks lke now 7 mos. later after adding established LR. Brian

 

^nice.....you better grab a case of snickers bars.....thats gunna take a minute

 

Thats a cool lookin piece! I would just build a giant cone and let it cure then shoot at it birdshot to give it a more natural look.....hmm maybe we need to have a rock making party at craigs so we can shoot stuff.

 

i really want to make some rock as well... someone should write up their successful recipe and curing process...

arent the waterloo people supposed to make rock in a few months? if someone writes it up id rather start it now so itll be done sooner...

 

Its not hard to make, but it does take a long time to cure (took mine about 2 months).

First off.. forget what you may hear about using macaroni to create the natural porosity of the rock, its a huge pain to get it to dissolve out. Instead, use water softener pellets as it will dissolve out a lot easier and not hurt anything if it doesn't.

The recipe I used was (roughly)

1 part - type I Portland cement
3 parts - play sand (there is a debate about silicates in play sand causing algae issues, fyi)
1-2 parts - crushed coral (Get crushed oyster shells from a feed store.. much cheaper than buying commercial)
1-2 parts - salt pellets
And, of course, water

All I made was base rock so some of it was put on cardboard and has a flat bottom. I did use my horseshoe pit to make a few caves, but what I can say is that it will be very difficult to make a rock shaped like your picture unless you are using clay/ceramics and a kiln. The problem comes, as mentioned before, when the rock dissolves from being mixed too dry to properly complete the chemical process of the cement hardening.

Once its dry (24 hours usually), place it in a trash can, fill it with water and change it daily. The pH is going to be off the charts and this is what the "curing" process is all about.. leaching the pH back to acceptable levels. Start testing for pH after a few weeks and the test will tell you when the rock is ready.

Personally, I would hold off until spring if you can unless you have a place warm enough to prevent the water from freezing.

There is also a decent thread in the DIY on RC, but as always there are 4000 pages of dribble and 15 pages of good information. I tried to put here the important information. Feel free to PM if you have a question on anything here.

Jeremy

 

Covey is very up on rock making techniques ....might want to shoot him a PM.

eins

 

i made approximately 160 pounds of rock for about 70 dollars.

the most expensive part is the arrgonite sand.

i used arrgonite sand
portland cement
crushed oyster shell

i used 2 cups portland to 6 cups oyster and 2 cups arrgonite.

i used arrgonite also to make the molds so arrgonite totally covered the rock.

its pretty easy to make, just dont pack it down, just drop blobs of the mix on top of blobs to get a lumpy jagged look too it.
i also used a bunch of shells i picked up on several different beaches in florida and stuck them on the rocks, they were the first things to get corraline started on them.
i thought it was a cool addition since i never would have used them for anything else.

if you want tall peices you should use something like a 5 gal bucket and stack droplets on top of each other then cover with dry sand as you go to support it.

you can make any shape you want really, you will have it figured out really well by the time you are done, LOL.

i opted not to use rock salt but looking back i wish i would have.

i made mine in march or april of last year and it finally cured in august, i had it in a kids wading pool out in the yard, the first couple months i suggest changing the water as much as possible because the lime leaches out fast at first.
check you ph from the tap and when you do a water change after 2 days the ph is the same as tap it is done curing.

you should let it sit in saltwater after the cure also because it dose leach again when it goes into salt water, mine did anyways.

now that i know how to do it, i could have done better.

i like marco rock, you cant beat it, if i were you i would buy instead of making it, its a long wait and you probably wont be satisfied.

 

Posted By got2lb on 01/14/2008 6:37 PM

Posted By Waverz on 01/13/2008 10:14 PM
Thats a cool lookin piece! I would just build a giant cone and let it cure then shoot at it birdshot to give it a more natural look.....hmm maybe we need to have a rock making party at craigs so we can shoot stuff.
That's awesome!  Now that's my idea of a rock making party!  Not sure how the lead pellets left in the rock would work out though. /site/DesktopModules/NTForums/themes/_default/emoticons/wink.gif src="/site/DesktopModules/NTForums/themes/_default/emoticons/wink.gif" align=absMiddle border=0>
me and my friends have airsoft guns that could do it though and plastic bbs shouldnt be bad

 

Yep I made like a whole bays worth. It takes forever but you can't beat 100 pounds of rocks for $12. The real thing I like is if you plan it out you can make custom rocks. I needed a rock to go in front of my overflow. I made a rock that was 22 inches tall only 8 wide and had a stable flat bottom. How long would it take to find that rock or for that matter any other you need.

Anyway my rock was 3 to 1 portland to salt.

Mix the portland to a play-dough like consistency add salt.

I mixed it free standing.


let them air dry for two days


Soaked in a tub for a 1.5 to 2 months. Changed manually for the 1st week daily after that I lets my RO waste water run thru it and that was it.

2 months later slowly add to the tank making sure your pH doesn't (most of you guys want your pH higher right).

Anyway happy I did it I got a grand scheme for my dream tank for any all DIY rock system

 

With a decent drill and a masonary bit this stuff drills quite easy. So adding holes and tunnels is pretty easy

 

hopper when you bought yours did it already come pre soaked or did you have to soak it first,

 

Posted By fnvarner on 01/16/2008 7:57 AM
hopper when you bought yours did it already come pre soaked or did you have to soak it first,
The Marco rock is not diy rock, it's actual Fiji rock that is dried. He does recommend curing it before adding it to an established system, check out the FAQs on his website. If you want any additional info feel free to PM me. 
Brian

 

When making the rock using rock salt, to make large crevices would it be possible to like mist a bunch of the rock salt and get it to ball up? Ya know make a larger piece of salt using a little bit of water and getting them to stick. That way you could make some really natural looking caves and holes? Just an idea that probably won't work!