DIY Aquarium backgrounds

[EPringle]

So I have been doing some online research about making 3D aquarium backgrounds, using styrofoam and cement.  They look fantastic and seem simple enough to make but I am concerned about leaching toxins into my water.  Any thoughts?
I know Youtube has some excellent video tutorials but none of the ones I have watched so far really cover the topic of effects on water.

[johnrt]

You did not mention if this was for salt or fresh water, but either way.

See this page of this thread:
http://www.reefcentral.com/forums/showthread.php?t=1286738&page=21

An towards the bottom is a FAQ called:

v9.0 FINAL VERSION: Aug - 14 - 2008

Hope this helps.

[cichlidicted]

I am not sure of this can work or not but i also did the research once .... what i was concerned about is the PH .... but since it was going in 110 emptying tha tank and filling it again 10 times is very very time and cost consuming ..... my conclusion was if i was ever gonna do a 3D background it'll be this time of the year ... and i'll leave it all summer outside so that the rain will wash everything of it ... but like i said, am not sure if this would help toxins or not.

goodluck.

[RoxyDog]

Aquaviewer had a nice one in his 125gal, not sure if there is a thread about it or not, but perhaps he will chime in on this.  I have a rock structure made from DIY cement rock, great stuff foam and epoxy.  There are "toxins" at first but they went away quickly.

[KrazieCanuck]

I built the foam wall on my 90g and haven't seen any problems with it.  It's been in there for 3 months now and I'm starting to see a lot of good coraline algae growth on it.  I also hid my return pump plumbing in the wall, placed some rock and put a couple 1.5" PVC 45 degree tubes for some small tunnels.  My Blue Hippo Tang actually hides / sleeps in them sometimes and some of the other fish swim through them.

I'll try to post a picture or two when I get a chance.

I used the following items when building it.
- Great Stuff Foam (Red Can purchased from Homedepot or Canadian Tire)
- Z-poxy to spread on surface of cured foam to seal and stick sand to it. (Purchased from DynamicHobbies)
- Fine aquarium sand sprinkled on the Z-poxy to give it a more natural rocky look. (Pruchased from Big Al's)
- Some dry (tonga?) rocks (Purchased from Big Al's)
- Egg crate purchased from Rona
- GE Windows and Doors Silicone I (Blue Tube) to attach to back of aquarium glass and seal around the edges. (Purchased from Homedepot)

I did a bunch of research on this prior to building it and taking the risk.  The items above were items that quite a few other people have used with success.  So far everything looks good and the fish/corals look healthy.  I haven't noticed an pH problems.  That being said, this is a "do at your own risk" and I claim no responsibility if thing don't work.  The real test will be to see how this all stands up over a few years.

Check out the following link from OttawaInverts.  Very informative and explains how to do it step by step.

http://ottawainverts.com/2008/12/13/building-foam-rock-walls/


Good luck!

[Brent Shaver]

I have been looking into building one for my 110 cichlid tank.  I am looking to reduce wieght and of course ease of cleaning.  Its very labor intensive to remove and rebuild 100lbs+ of rock.

The one product I know that has zero toxins once cured is fiberglass resin.
(Has to be completely cured of course)

When I am ready I will get some thick styrofoam (insolation grade) in a large sheet and carve the backgound out in one piece.  Once that is done I will coat the whole thing with the resin and once it gets to the tacky stage will add some sand to give it a real look.  You would have to use a couple colors of sand inorder to keep the color accents for shaded or darken areas to remain realistic.

The resin will in fact cover and protect any paint you should use to color your background, as long as you leave no openings for leeching.

I hope to complete the background this summer as it is better to do outside as it will stink up a house bad if you do it inside.

I am going to build one for a small 20 gallon first, nothing fancy and add some tetras for a couple months to confirm everything I have read holds true.  I am not worried about the resin leeching toxins as much as I am it working well in the tank.
Once I get it done I will post picks for sure.

[Aquaviewer]

Just a couple of points off the top of my head that I noted in researching and looking at a number of DIY backgrounds in addition to some tips I picked up in making mine (sorry no photos).  I know that there are 100s of other ways you could do this, but this is what worked for me using the foam and cement method.

•    If you want it to look real you have to observe how rocks look, this includes studying photoss going out and taking photos of rock out crops, rock piles etc. and studying them, how they are composed, texture, colour, dimensional composition.  Many backgrounds fail because they look flat as most end up looking like a 2D picture of rocks as opposed to real rock.
•   Sticking rock bits and sand on epoxy will look exactly like that, rock bits and sand stuck to epoxy.  If you are using cement, spray foam or paint or whatever you choose to cover your foam, use the the epoxy at the end  to seal it all in.
•   You have to be prepared to give up space in the tank to get a good 3D effect and give your rock scaping texture. Fortunately building up foam to hide the plumbing encourages you to do this.  Some areas of mine I left flat as I knew I would have real rocks covering the areas.
•   If you are using foam sheet stock, instead of getting one sheet of foam and carving into it, use a thin sheet as the base and build up the foam in layers where you want outcrops using silicon and foam off cuts and then carve into it.  You can roughly cut the foam to shapes as you build up these areas.    I made a dawning of what I wanted it to look like as a guide. 
•   When you are carving make the spaces, cracks and crevices larger than you want in the finished product as you will be back filling them with cement later and that's when you will refine and smooth shape and texture.  To carve anything goes from sharp knives, rasps, propane torch whatever...  If something breaks off reattached it with silicon or cement, or you don't like the look of an area, cut out that section and add new material and start over.
•   You can buy colourants for concrete which are useful.  Make up small batches of cement with different colour concentrations and then apply in layers to get to colour and tones you are looking for.   You can also use natural materials.  I used fine stone dust for some of my lighter colours.
•   If you are using cement, rough up the smooth foam areas and then apply coat #1 which is thin and watery over the whole thing.  Let it dry.  Coat #2 is thicker - use brushes, spatulas etc  to build up your background and texture.  If you are doing a big background do this step in stages to avoid having to mix up big batches of material.  During this stage you can also add more foam if there are areas you want to build up – remember cement is an adhesive.   Your final coats (this can be as many as you like) are thin and are used to fix up areas, add more colour, texture etc.....  I added colour at each step to help give depth.  I found dark colours in cracks/crevices help create the illusion of texuture and depth for the 3D look. 
•   I did not use epoxy as I did not want a glossy look.  If you go this route don't have plecos in the tank as they will wear away at the cement.
•   If you are building the background outside the tank remember to account for the bracing when you go to install it.  A piece of foam with cement and epoxy all over it doesn't bend around bracing.  I made mine whole (Six feet) and then cut it into three pieces before I did the cement.  Once installed I used extra cement to seal/cover the joins.  I let this all sit for a week or so before adding water.
•   Test the fit as you go. Test the fit as you go.  Test the fit as you go.  Test the fit as you go.  Particularly where the pluming is concerned.
•   If you are using cement it took about two weeks of water changes to get the pH down to normal.  This timeline is completely dependent on how often you change the water.  The pH peaked at around 12ish during the first soak and tapered off rapidly during subsequent soakings and stabilized around 8.  I treated mine right in the tank.  I used the waste water on my lawn with no ill effects.  Once the cement is cured the "toxic" leach folks are concerned about is not a factor.
•   I ran sponge filters in my tank for the first month (in addition to my canister filters), manly to keep the aeration up to keep the pH stable.  I added the fish about a month after installation and didn't lose any and they started breeding about a month after that (I had the advantage of having multiple fully cycled filters on hand)

There are a couple of good DIY background threads out on the net.  I seem to recall that there was a dedicated thread on RC which discusses the techniques and use of spray foam for salt water applications which would also have fresh water applications.

Happy building,

[EPringle]

THANK YOU SO MUCH FOR ALL YOUR REPLIES!
More research to be done before I try it out. But I will keep a log of step by step posts when I do in
case any body else wants to try it!  Should be fun!

[redbelly]

We build custom backdrops for tanks if you are looking for one made for you.

Here is a link for how to build your own using the foam and rock for the back of the tank. This is from a ovas member, hookup.
http://ottawainverts.com/2008/12/13/building-foam-rock-walls/