The Ultimate DIY Rocks!

[speckled trout]

Travis L. Stevens, your right. I have had my rocks in my tank for over two years. None have broken or should they. It's not like they're being required to hold up very much. Plus, water displaces a lot of the weight.
Too much worry about something that just isn't gonna be a problem.

 

[Travis L. Stevens]

<a href=showthread.php?s=&postid=7476258#post7476258 target=_blank>Originally posted</a> by speckled trout
Travis L. Stevens, your right. I have had my rocks in my tank for over two years. None have broken or should they. It's not like they're being required to hold up very much. Plus, water displaces a lot of the weight.
Too much worry about something that just isn't gonna be a problem.

That's true. But you have to admit. At least I've learned more than I ever thought I would about cement. It will come in handy I'm sure.

 

[Reef_|<eeper]

Travis..... did you ever stand on your rock to see if it could stand the weight? If so, I missed it and would like you to post it again. Thanks.

 

[captbunzo]

<a href=showthread.php?s=&postid=7476151#post7476151 target=_blank>Originally posted</a> by Travis L. Stevens
If you're willing, do a little experiment for me. Make some Type one rock and some Type 3 rock. Use the same ratios, but just use different cement. While curing, keep a detailed journal. Then we can find out first hand exactly how much better Type 3 might be.

I was planning on doing the comparison against my second batch, with curing times only being a week apart. However, since this is cheap enough and simple enough to try out, I'll go ahead and do the full experiment.

As for the Salt & Cement part, I will definately use a 3:1 ratio again. I think that worked really well. I will also throw some acrylic shavings in there as I really don't think that can possibly hurt anything. They might make the rocks a little lighter. And I really think the filamentous nature of the shavings will help the rock hold together better, especially at first.

Concerning the crushed coral as a part of the recipe, I really haven't made up my mind. I am tempted to throw a small part in there, maybe 1/2 of a part in the ratio.

But I'll have to think about it more. Also, I've gotta say that I doubt the crushed coral or shavings would weaken the rock much since neither will dissolve away. I mean, concrete is perfectly strong and it is filled with sand and gravel. I think the same discussion above about "100s of #s" of weight or not is the relavent point. If anything, the salt is going to weaken the rock as it dissolves away and leaves hollow spots. Of course, I think the benefit outways the problem there.

 

[captbunzo]

<a href=showthread.php?s=&postid=7476886#post7476886 target=_blank>Originally posted</a> by Reef_|<eeper
Travis..... did you ever stand on your rock to see if it could stand the weight? If so, I missed it and would like you to post it again. Thanks.

Uh, I weigh 160#. Travis can't be too much different himself. And I doubt that ANY single rock is going to support anywhere NEAR that much weight in the average aquarium.

Lets take a 180G aquarium for example. Let's say you went for a rock to water ratio of 1.5# / gallon. That'd be 270# of rock total. And let's ignore for a moment that our DIY rock is lighter then real rock.

If you divide the 180G tank in three sections that are 2x2x2 foot in space. And PRETEND that any ONE rock might support HALF the weight of the rock in that section, then ONE rock might be supporting 1/6 of the total rock in the aquarium. That'd be a grand total of 45#. That is a WHOLE lot less then an adult male in weight.

And I think the above description of mine is full of overcalculations as no ONE rock is EVER going to have that much weight on it in an aquarium. And DIY rock is lighter, further lessening the load. Etc, etc, etc.

Now, I do agree that our rocks are not going to be optimally strong, optimally hardened rocks. However, I consider this to be a non issue. I don't plan to throw mine around or stand on them anytime soon. But then again, I don't do that to REAL live rock either.

 

[Travis L. Stevens]

Exactly, Paul. That's what I was saying above. It's going to be strong enough even if we don't properly cure it for strenght. And for what it's worth, I missed that question earlier. I have stood on one of my rocks and it withheld my weight quite well. A few indentions and overhangs crushed, but that would happen with real rock. Paul, thanks for the flattery I weigh 250lbs

 

[ghever]

I am thinking of making a rock where I have a pillar like leg coming from the bottom, and then 2 flat shelves branching out of the pillar leg... Do you guys think I could use eggcrate as support for the branching shelves? I want the shelves to be pretty big.. maybe 6 to 8 inch x 6 to 8inch...

Also, is everyone now using the salt from home depot? Or the salt from wal mart?

thanks
G

 

[Travis L. Stevens]

It's definitely the salt from the LHS now. The WalMart is way too expensive and not pure.

As a suggestion, you could use eggcrate inside the shelf piece to give it added strength. It should be strong enough without it. As far as building the pillar, you could get a masonry drillbit from a LHS and drill a hole through all of your rocks and lace them onto PVC pipes. This will keep them together on a pillar without causing them to fall over. I'm thinking about doing something like that for my Montipora Only tank....but that's another thread.

 

[captbunzo]

I am not yet convinced at the need for "extra supports" built into the rocks, etc. I think with proper use of some sort of molding material (rock salt, crushed coral, sand, cheetos) inside a plastic tub, you can build virtually ANY shape out of the cement mixture. While I have not made any REALLY big pieces yet, I don't think that would be any problem.

One suggestion - try to limit the THICKNESS of any chunk of cement mixture in a piece of rock. I would guess that thicker pieces are going to take longer to dry. And, IMHO, they don't really look as natural either. I REALLY like pieces with lots of holes and nooks and crevices, etc.

Also, for good base rock pieces, using something flat on one side of the rock in your form is a good idea so it sits well.

Travis - btw, I realized something else good about using Rock Salt in the cement mix. In my reading, I ran into discussion on the need to cure the rocks in SALTWATER, since that is what they are going to be in inside our tanks and Saltwater reacts differently then freshwater with different things, such as cement. And while dissolved rock salt is not going to produce the same type of saltwater as we use in our tanks, it is probably a LOT better then curing Rock-Salt-less rock in fresh water.

Just a thought...

 

[Travis L. Stevens]

In order to cure the rocks to bring the pH down, water changes will be needed. As the pH increases, it will slow down the leeching. The base of freshwater is 7.0 (+/- a little). Like Calcium Carbonate (IE aragonite sand), the pH needs to be low enough to dissolve it out until our rock can reach a safe pH level. In short, I don't think curing it in saltwater or salty water is going to help if not hinder the progress. At least for the first week, I recommend doing anywhere from 50-100% waterchanges on your curing bin. I could be wrong though. I'm not a chemist *cough* Randy Holmes-Farley *cough**cough*

 

[Barto]

Here is batch 1 starting it's wet cure on a cracked 10G.
I won't put them in the creek till I have at least a milk crate full.
The excess water is going to a 65' pine tree in the back yard, I usually deep/slow water the big trees like this at least 48 hrs a week. We have 3 of the big ones.
I have a drip of about 2-3 gph going thru the tank.
I like the looks of the porosity that I can see right away.
Great points made a little earlier about not having to compete with mother nature for who's rocks are stronger. I have to agree that ours are strong enough for our use

 

[Travis L. Stevens]

I can see where you broke one. How do you like the exposed inside? Pretty nice, huh?

 

[Barto]

<a href=showthread.php?s=&postid=7477279#post7477279 target=_blank>Originally posted</a> by Travis L. Stevens
I can see where you broke one. How do you like the exposed inside? Pretty nice, huh?

Yup!
Kind of like an english muffin, lots of nooks & crannies
I'm out! Had some phone calls & desk work this AM, back to real work!

 

[Insane Reefer]

I have NEVER heard of Anyone curing in saltwater and agree with Travis that the salt actually will slow the process.. It all about the PH, Babieeeee.

 

[Rhodophyta]

<a href=showthread.php?s=&postid=7349326#post7349326 target=_blank>Originally posted</a> by WIJAONKA
Okay, The rocks look GREAT!!

I live in Las Vegas where the popular type of Portland Cement is Type V.

My question is this:

Does the cement 'type' make any difference in creating rocks? I understand that it needs to be 'portland', but does it have to be type I??

Thanks,

W

the advantage of using type V is that it's low alkalinity. It should lose it's excess buffering capacity sooner if you need to use it in your reef tank ASAP. It would be ideal for freshwater tanks. White Portland cement is similar and produces a lighter color rock that looks more "natural" to most people.

 

[Savatage]

QWIV: What kind of accelerator would you use in the rock or water

 

[Rhodophyta]

<a href=showthread.php?s=&postid=7480457#post7480457 target=_blank>Originally posted</a> by Savatage
QWIV: What kind of accelerator would you use in the rock or water

Calcium chloride is the most common accelerator. There is also a high tech polymer accelerator.

 

[Travis L. Stevens]

<a href=showthread.php?s=&postid=7481429#post7481429 target=_blank>Originally posted</a> by Rhodophyta
Calcium chloride is the most common accelerator. There is also a high tech polymer accelerator.

So you're saying that my Homemade Two Part system can also quickly "dry" my rock? How does it work? That would be great to use for intricate shaping.

 

[captbunzo]

hehe - I hadn't looked yet. But I THOUGHT Calcium Chloride was what I use in my Randy Supplements...

 

[bnplu]

I am confused about one thing when making this rock with salt. When curing this in the water I know that the salt will dissolve if exposed to the water but what about the salt that is in the rock. Will it dissolve while it's curing or will it eventually leach into the water six months down the road?