The Ultimate DIY Rocks!

[Travis L. Stevens]

I don't use a mold. I free hand it. When making rock for a new tank, I purposefully make a fair amount with flat bottoms. These can go under the sand on the tank bottom, against the back wall, along the overflow, etc. This provides a wonderful area for 'pod growth in the tank since fish can't get back there to eat them. As far as the 360º shaped rocks, I build the with a flat bottom, let it dry a little, and then carefully pick the rock up and shape the bottom.

 

[Fishboy1230]

Oh sorry I thought you used molds. I havent used any to date yet, but i plan on trying using some old 6" pve halves with added details as a mold.

 

[Travis L. Stevens]

I'll be using a mold eventually as I prepare for mass production. I've used various molds before, but none of the rocks came out to my liking.

 

[Nammy]

Have any of you guy's though of using Baking Powder in the mix?

Baking Powder is a dry chemical leavening agent used in baking.
When dissolved in a wet mix the acid and alkali react and emit carbon dioxide gas, which expands existing bubbles to leaven the mixture. Most baking powders are double acting, that is, they contain two acid salts, one which reacts at room temperature, producing a rise as soon as the dough or batter is prepared, and another which reacts at a higher temperature, causing a further rise during baking.

When mixed in the “DIY rocks” wet mix, it should start some bubbles and as the rocks cure, again create more bubbles. Bubbles = porous rocks, right?
Just a thought.

 

[Insane Reefer]

<a href=showthread.php?s=&postid=9299275#post9299275 target=_blank>Originally posted</a> by Fishboy1230
...i plan on trying using some old 6" pve halves with added details as a mold.

Like this one? :lol:

I used a hot glue gun to add said details; I tried to think in reverse and built layers up. I also added a bit of pasta and a couple of shells. Don't know if they will have any impact or not. I then mixed pure silicone with mineral spirits and made a thinnish paint and have covered it.

These are tall enough to be used against the bottom of a tank within the DSB, and provide "corrugated" support with water flow possible under the massed rocked above. At 14" long, 6-9 of these could be used in a 75g to provide a stable footwork. Or you could add 1 or 2 into your rockpile for eels and the like.

Will post the rocks I get from this as they are ready

 

[Insane Reefer]

Just got this done and cured and ready to fill
Now I am procrastinating, lol. I still have rock to make for this, so it will only have the few pieces of LR I bought to seed with. Sorry the photo stinks - my camera is old and tired. And yes, my backwall is square.

I made this backwall for my 8g nano with a no salt recipe made with portland - I wanted to go as thin as I could and still have strength; these measure 1/4" to 1 1/4" in depth. I made it on plastic covered glass, with a puzzle like pattern drawn on paper under the glass to keep it all sized right. After a week in a bag curing, it was removed to my toilet tank, and it kured in 3 weeks.

A muriatic bath and scrub and a saltwater soak for a few days, and this is what I got. I used aquarium silicone to glue the pieces on. I thought about epoxy, but I may decide to do something different and want to be able to get them off. The silicone will suit for the purpose. In hindsight, I should have added magnets to the backside while casting so they would be flush, but I didn't. Oh well.

I like it. Once covered with coralline, it will be really cool, IMO

 

[customcolor]

Not bad at all for first tries, Customcolor

Looks like you hand smoothed the surfaces? That is one advantage to the salt/cement only recipes - you don't have to worry about not compacting the cement so much, so smoother shapes are easier to make...

no i didnt hand smoothe the surface, the cement mix was soupy for my first trys but im trying dryer mixes now like my big one. i think i will make some more in a few days and i will take more pics of it all the newbies that just dont wanna read a ton of pages like i did.

 

[Icefire]

Did someone tryed Perlite or Vermiculite?

 

[Insane Reefer]

Sodium Bicarbonate is a salt, which we know weakens cement and messes with its natural curing or hardening process. We have overcome this to a greater degree by using solar salt, which seems to not leech into the cement so badly. Our rock is still not something you'd build a house on, but strong enough for our needs.

Now in researching with google, it has been theorized, but never actually tried (to my knowledge), that if one could get large enough chips or chunks, marble sized or so of Sodium Bicarbonate, that this might work. But just adding it in as a powder most likely will result in even more brittle rock, with no noticeable increase in the number of pores. Maybe you could try the larger bits and report your results, Nammy?

Icefire, we covered vermiculite a few pages back, and it isn't a good choice. Perlite might be a better choice, but certainly not an economical one.

 

[Icefire]

Perlite cost next to nothing... 10$ for about a 50G of it.

 

[Insane Reefer]

And what benefit would you hope to gain from using Perlite?

 

[Chasmodes]

<a href=showthread.php?s=&postid=9264617#post9264617 target=_blank>Originally posted</a> by Insane Reefer
Hey - since this has morphed into a temporary Blennie thread, want to ask about Bi-color Blennies. Anyone had them, and if so, are they a good choice for a nano?

Sorry IR, I didn't see this. I responded to you in an PM. I didn't want to hijack the thread with my blenny posts.

By the way, your summary was excellent. And Travis, let me just say that you have inspired me from the first post. This is a very informative thread, lot's of great ideas by all!

 

[Icefire]

Lighter rock, some place bacteria could colonise.

I bought some 3min set hydraulic cement and didn't find oyster nor good sized rock salt.

So it mostly for use as a filler.

 

[KyleP]

<a href=showthread.php?s=&postid=9280343#post9280343 target=_blank>Originally posted</a> by GuySmilie
KyleP, did you ever try the 2:1 ratio?
I wonder what results you got, if you did so?
Guy

Yes, I tried it the other day. Its currently sitting in water. It turned out pretty good with the 2 (quickwall) : 1 (sand) : 1 (salt). But I think I could have got away with more salt. 1.5 salt or maybe even 2 parts salt. Be careful with the cement for the first two days. I broke a branching Tonga type design because I lifted it out of the mold too early. Give it at least two days. So far I have only made a seven inch by 4 inch table rock and a bunch of frag disks. Wanted to get the ratio down first before I get into the more elaborate designs. I have made rock with portland and crushed shell, but this Travis's recipe is definitely more porous and light.

 

[Travis L. Stevens]

Yes, I've had a few rocks float now because it was so porous.

 

[Insane Reefer]

Ok Icefire, 4 minutes with Google and this is what I come up with:

Perlite is not a trade name but a generic term for naturally occurring siliceous rock. The distinguishing feature which sets perlite apart from other volcanic glasses is that when heated to a suitable point in its softening range, it expands from four to twenty times its original volume.

This expansion is due to the presence of two to six percent combined water in the crude perlite rock. When quickly heated to above 1600°F (871°C), the crude rock pops in a manner similar to popcorn as the combined water vaporizes and creates countless tiny bubbles which account for the amazing light weight and other exceptional physical properties of expanded perlite...

...Since perlite is a form of natural glass, it is classified as chemically inert and has a pH of approximately 7.

So could you use it? Yes, most likely. Would there be problems? Not up front, but I think you will end up in the long term with "Bio-Balls". But like I told Nammy, Try it, keep scientific notes on the process and post what you learn - then we all learn.

 

[Insane Reefer]

Speaking of "BIo-Balls", I was dropping off a load of rock to the LFS, and got talking to a guy, who could say nothing but bad things about DIY rock. He claimed that over several years they become "$hitballs" and nuked his tank - and that he wasn't the only one with this problem. I pointed out that Aquariums use the stuff, and he came back with something about hiring divers to blow the rock with an underwater equivalent to a leaf blower. I wasn't really sure what to say to that. It got sort of nasty.
Any thoughts?

 

[Travis L. Stevens]

I agree and disagree. But this goes for any rock; live, base or DIY. It also directly relates to aquarium husbandry and maintenance techinques. If you allow any rock to become "clogged" with nutrients, it will eventually push it back out. But, in order for it to get clogged, then there is inadequate maintenance and nutrient export.

 

[Reno Reef]

I just got to the end of this thread. And it only took me an 8 hour shift at work one day and now 3 hours into my shift today.

But first I must say that this has been the best thread I have read on RC. So many other threads seem to end up with alot of bickering and ego trips.

This thread was hands down people trying new ideas and helping each other out. I commend and thank everyone who has taken part in this thread.

I have a 80G freshwater that will in time become a reef (when all the freshies die of old age so maybe years) so this gives me plenty of time to work on rock. And before I found this thread I was trying to figure where I was going to come up with between $400 - $600 in rock to start the tank.

Thank you everyone this thread has really inspired me. And also made me think of one question. I Have a bag of old brown sugar that is rock hard. Does anyone see a problem with mixing it into the cement mix implace of the salt? Just an idea I thought of. I will hopefully be making a trip to HD or Lowes tomorrow.

Thanks again everyone!

 

[Rhodophyta]

<a href=showthread.php?s=&postid=9308021#post9308021 target=_blank>Originally posted</a> by Insane Reefer
Speaking of "BIo-Balls", I was dropping off a load of rock to the LFS, and got talking to a guy, who could say nothing but bad things about DIY rock. He claimed that over several years they become "$hitballs" and nuked his tank - and that he wasn't the only one with this problem. I pointed out that Aquariums use the stuff, and he came back with something about hiring divers to blow the rock with an underwater equivalent to a leaf blower. I wasn't really sure what to say to that. It got sort of nasty.
Any thoughts?

It sounds like he was out to contradict anything you said. Usually when something goes wrong with our tanks, it is our fault, not the equipment, the methodology, or the livestock.

We have to watch, maintain, and react quickly to warning signs. There are people who cannot accept that, and must find something or someone else to blame. When you begin to poke little holes in their defense mechanism, watch out. Nasty is only the beginning.