# Finishing DIY cement "rock" background



## MrsBee93

I am working on a "rock" background for the cichlid tank. I've been following ideas and instructions from several DIY articles on the web.

A couple articles suggest sealing the finished background with epoxy resin. I'm not comfortable using that, but I'm also not sure I want to just put the background in my tank, as is, either. I've read that some fish like to play with the concrete and eventually make it come off in little pieces.

I used 2" pink foam insulation and I'm putting several thin coats of hydraulic quick stop concrete, colored with brown pigment. My tank is 55gal... no fish or water yet. After the second coat, it's definitely taking on the look of a rocky wall. I'm going for a Lake Malawi look. So far, I'm very happy with how it's looking.

At the hardware store today, I was looking for other options and found a concrete sealer that is silicone acrylic, clear, and waterproof. Quikrete has a sealer that would do the job.
Is there any reason I could not use this? It can be used within hours of pouring concrete, as it helps the curing process and seals at the same time.

What ingredients should I watch out for? Do you have other ideas? 

Thank you for any advice!


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## Guest

Sounds sweet. How heavy is this thing? 

It would be easier to know what's in the product than list what you should look out for. All I could find on the internet was "Acrylic water-based", but not what else might be in it. Is it possible for you to get a list of what's in it?

Do post pictures of the wall, if you can


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## MrsBee93

It actually isn't too heavy at all. It's in 3 pieces, so it's manageable. I do need to take some pictures...

Here is the MSDS sheet I found for the Sealer. It doesn't make sense to me, but maybe it will to you? :lol:


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## MrsBee93

If I go with resin epoxy, how would I apply the stuff? My background has lots of caves and nooks and crannies... can it be brushed on like paint?


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## MrsBee93

checking to see if my pics have uploaded... 

okay, they're pictured from left to right, how they'll go in my tank. The wet look on the middle piece is because I just finished spritzing it with water to (hopefully) prevent cracking.

Still looking for options to seal the pieces. I just read that Thoro Seal is a good product and dries inert, so it's safe for aquariums. My only problem is that it's not clear. I think it's white.


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## Guest

Either I'm blind, or I didn't see the list of what the sealer's made of on the MSDS sheet. It did say that it's harmful if let into waterways/sewage systems, etc, but I'd imagine that's in the uncured form.

Epoxy can be applied with a brush, as far as I know. I wouldn't use a sponge type brush, just a traditional bristle brush you'd use for painting.

Nice looking background. Can't wait to see it in a tank  Good luck!


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## akangelfood

Looks great! I've always been a fan of those backgrounds. You've done a wonderful job!


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## joe kool

mrsbee ... I would call the number at the bottom of the pages and ask if the cured product can be used in concrete ponds and aquariums. I say ponds as they may not under stand the concept of what you are doing but most folks will have an idea on a pond or at least be able to point you in the right direction.

BTW ... I'm envious of your talent. :mrgreen: I have to use flat pieces of lace rock with a few other things to create anything close to that. NICE JOB!


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## Bartender

MrsBee93 said:


> If I go with resin epoxy, how would I apply the stuff? My background has lots of caves and nooks and crannies... can it be brushed on like paint?


Yes, you paint it on with a brush. However, buy the cheapest brushes you can find because you will throw them away after use. Once the resin hardens on the brush it will be hard as a rock. Hope this helps.

My first post btw. Hi everybody!


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