# DIY Foam Rock



## paddyc1 (Feb 3, 2013)

Guys, I've been thinking of constructing foam rock for my Malawi Cichlid tank.
The main reason being, I have a lot of rock in my tank and I've recently been thinking that if a rock was to shift or fall, not only could my tank/fish be destroyed but also my living room.
Has anybody any experience of doing such ?
Any info welcome.
Paddy


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## Steve C (Oct 9, 2011)

I've done it, The main thing is to just make sure you really silicone it good to the bottom of the tank or else it will pull free from the buoyancy. The main drawback to doing it is you can not move the "rocks" around. It might not seem like a big deal now but everyone gets bored with the same setup all the time and eventually you will wish you could rearrange your aquascape which you wont be able to do. Also netting fish in a tank that has rocks which can not be moved is not fun at all.

My honest opinion. I did it before but would not do it again for the above reasons. Just stack your real rocks correctly and if still worried then put some egg crate down to protect the tank. 3D backgrounds are great, foam rocks that are not moveable, kind of a pain in my experience.


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## apmorgan93 (Jan 29, 2013)

Just an idea, but could you use anything to weight the "rocks" enough so that they didn't float?


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## matt duarte (Aug 29, 2013)

heres some pix with what I was doing... haven't painted them yet









Styrofoam and a steak knife.. drylock and quikcrete concrete paint.... with a nice amount of silicone and firmly held to the bottm of the tank for a few days to a week for a proper cure and I think it would hold.. *** done it on my 115gal siliconed one big Styrofoam rock to the bottom of the tank and its been good for over 2 years


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## chmey (Apr 29, 2010)

I can't find the post, but awhile back someone talked about using the expandable spray foam over a heavy rock.
The rock weights the structure down and the foam can be shaped while wet.


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