Fake Rocks

[ChrisEddy85]

Hey all,

Just wondering what anyone could suggest I use to make fake rocks. I would need something that was easy to mold, would set hard and not break up in water, and would also not affect water conditions, or if it would, it should only soften the water and lower the pH.

First thought that came to mind was natural clay, but I don't know the properties of this, so chances are its highly alkaline and full of calcium ready to ionise and make my water hard... haha.

Tell me what you think.

[AHC]

Hi,

I started doing a little bit of research on this as im going to be making a centre peice type cave and decided to make it as it will be hard to find what i want. Making a rock will also be lighter and spare me some water loss based on the density.

The best idea i read was to carve a polystyrine block into the shape you want. Then cover the outside with epoxy resin or similar, colour/rub dirt or sand into it and then another layer. I plan on doing this but doing it so the foam centre can be taken out (which will allow water tio fill inside the rock and wont take water from my overall amount). Having the inside of the rock hollow means i can have a little access for smaller friends like khulies or something to have it as a hideaway.

Anyway, my point is that from what i have read, making it using a water proof/non toxic material will be the best way. if you google "making rocks for aquarium" or something like that then you will get a lot on it. Or if your in no rush then you can wait for my journal where i will have my approach detailed. Im currently making a light while i wait for the tank to be delivered from one of our sponsors.

[ChrisEddy85]

So you suggest making a mold out of polystyrene, covering it in resin and then removing the mold? How would you remove it? I haven't worked with epoxy resin before, but I imagine it would bond to the foam.

Also, I have heaps of high-density polystyrene, which I imagine would work better than the low-density stuff you get with packaging etc.

[AHC]

Yeah the high density would be much easier to mold and get the lines associated with a natural looking rock. A few of the DIY Rock methods i read kept the polystyrene inside the mould. The problem with this would be getting the rock to stay submerged. I have not found a pre-coat product yet but will invest some time to more research just before i start the project. Leaving the bottom of the mould open should also allow room to rip out the foam and clean the inside. Just be sure to incorporate a lip around the rock which can be held down by the substrate or other items like Drift wood or stones.

Other methods include making them from a sandy concrete mix and i think sealing that.

I just had a quick search to try and find the sites i visited but couldnt. I will spare some time this afternoon or tomorrow to get the sites which will help you. :)

[ChrisEddy85]

I plan to make one to hide my overflow in my 2' high tank I'm building, but also incorporate PVC tubing inside for caves, and then potentially making an acrylic backing, so that it can be pressed up against the glass for viewing.

[AHC]

The possibilities are endless, they look great, seem easy and will be satisfying to make a custom rock suited to what you need.

Try these:

http://www.aquatic-gardeners.org/TAG20-1pg25-31.pdf
http://www.sydneycichlid.com/fishtank-background.htm
http://www.cichlid-forum.com/articles/diy_background.php

I got the last 2 links from a thread on aquarium life if your a member. I hope its ok if i list it here . (Moderators please remove if its not - sorry)

http://www.aquariumlife.com.au/archive/index.php?t-6719.html

This is a start for you. Enjoy!

[ChrisEddy85]

Some good ideas on the first one, although seems like a lot of work for minimal return. There must be an easier way.

You're right about the second, wouldn't open.

[AHC]

if you or anyone else find an easier way - let me know :D if i find easier methods when i do more research then i will post back here.

i did see some stuff on making backgrounds - similar method but maybe simpler. Im sure there are many vairations to the latex/resin kind of fake rock.

Good luck

[AHC]

Hey Chris,

Found some more links for ideas. The first one seems easy. However instead of filling in with plaster, paint on the cement, epoxy etc so that its hollow.

http://www.modeltrain.com/rubbermold/rubbermold.html

http://www.plecofanatics.com/forum/archive/index.php?t-17916.html

http://www.aquariacentral.com/forums/showthread.php?t=111484

Anyway, let us know how you go.