# Styrofoam aternatives for diy background?



## tokyo (Jan 19, 2010)

Does anyone have any ideas for how a diy background could be made without using styrofoam?

I am trying to make a DIY background for a plywood tank and I am worried that if I silicone the background to the epoxy/fiberglass interior it will make a mess that will be next to impossible to remove. On glass atleasy you can use a razorblade to scrape it off. I don't know how you would romove it from epoxy.

I am trying to come up with a background that could just be set in place, or maybe attached with a few suction cups near the edges. So it couldn't be buoyant at all. I was thinking of using plexiglass to create the backing, but I'm not sure what I could use to build off of that.

Any ideas?


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## cjacob316 (Dec 4, 2008)

http://www.cichlid-forum.com/phpBB/viewtopic.php?t=216010

this is the best i can offer atm. there won't be anything you can carve and shape other than styro, or large sponge (like the t-rex accessories http://www.petworldshop.com/t-rex/rex-rock-ridge-background-gallon.php)


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## tokyo (Jan 19, 2010)

Well, if I did do a styrofoam DIY background is there a different, less permanent, way I could attach it?

I guess if I just make sure I do a really good job on it I would be ok with siliconing it to the tank. Its just that this project has taken alot of time and effort and I don't want to ruin it by attaching a diy background I may later want to remove.


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## mightyevil (Oct 23, 2008)

One thing I can think of and I don't know how possible this would be...

Buy something like play-dough or some of that ceramic paste or whatever its called, make a block as big as your background (unless you want to do it in pieces), grab some real rocks and start indenting the dough. Once done, make a frame around the sculptured dough and pour some cement on it. Let it dry for many days, many, many days and when all done hose the dough off!

Again, I don't know how possible this would be but it is an idea!


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## cjacob316 (Dec 4, 2008)

make a plaster mold for cement lol


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## FlyHigh (Nov 15, 2009)

Why not make your background out of styrofoam and then silicone the back of the background to a thin sheet of plexiglass? Add a lip or base to the plexiglass that would come out a few inches on the bottom. Kind of like an "L" shape if you're looking at the tank from the side. Inside the "L" would be your styrofoam background but along the joint of the "L" you could install a strip of weights so that the whole background would not float. If you ever needed to get behind it, you could just slide the whole thing out. Not sure if I described it well. If the back of your tank is 6' by 2' for example, you would have a 6X2 sheet of plexi with a horizontal foot attached to it that ran the length of the tank (6' in this case). It could come out however many inches you background will be thick. Just leave room in your background for a strip of weights to be siliconed down to the plexi base, probably at the joint of the "L" before you encase it with the styro. Make sense?


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## tokyo (Jan 19, 2010)

Makes sense, and isn't a bad idea, but you would need a lot of weight to hold down an entire styrofoam background, that stuff is extremely buoyant. Also, silicone doesn't adhere well to plexiglass. Although I'm sure there is an alternative adhesive that could do they job.

I really like the molded cement idea. I think I'm going to save that one for later when I have more time to experiment. My stock for this tank is coming in pretty soon, so I need to get this done within the next two months. Which sounds longer than it is.


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## Malawi_Junkie (Nov 26, 2009)

Here is a link to one a member built using real rocks set in a resin that is non-buoyant.
http://www.nycichlidforum.com/build...978.html?sid=fd9c1883235585d0b218803318e0a4ab

IMHO You would need way too much weight to hold one down with the L shaped foot idea for it to be a viable option.


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## tokyo (Jan 19, 2010)

Would *THIS* be ok to use? I can't get large sheets of styrofoam, so this is the best I can find.

Or where should I look to find sheets of styrofoam?


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## cjacob316 (Dec 4, 2008)

that works


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## Eclipse5161 (Feb 4, 2007)

tokyo said:


> Would *THIS* be ok to use? I can't get large sheets of styrofoam, so this is the best I can find.
> 
> Or where should I look to find sheets of styrofoam?


thats what im using for my project.


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## Mcdaphnia (Dec 16, 2003)

You can get a 4" thick Poret sponge, cut out pieces of it and then use the cut outs on remaining flat areas to create overhangs. I would stitch through it with nylon yarn to hold it on, the same stuff killifish and rainbowfish keepers use to make spawning mops.

The sponge can be just bigger than the inside width of the tank to hold it in place, but the coating should not quite reach the edges so it doesn't scratch the glass of the tank. Leave a few inches at the bottom uncoated, and put a lift tube in the sponge to circulate water through it, Mattenfilter style. Conceal the sponge at the bottom with rocks in front of it, or gravel.


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## FlyHigh (Nov 15, 2009)

Malawi_Junkie said:


> IMHO You would need way too much weight to hold one down with the L shaped foot idea for it to be a viable option.


I was thinking something in the lines of a 2" diameter solid metal pipe running along the "L". In my mind it would work, but you may be right, even that might not be heavy enough.


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## Malawi_Junkie (Nov 26, 2009)

You could test your theory by taking a small peice of styro and see how much weight it takes to sink it. Keep in mind that floating docks are suspended with styro. I under-estimated styro on my first DIY BG and didn't apply nearly enough silicone (only 5 tubes on a 220gal.) and it busted up out of the tank. There were 2 parts left in the tank and I couldn't even force them down enough to remove them with out draining my tank. Not to knock your idea just saying a whole lotta weight would be required.


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## Rick_Lindsey (Aug 26, 2002)

How about sand-casting a solid concrete background? Or if that's too heavy for you, mix perlite or somesuch with the concrete to make it less dense.

-Rick (the armchair aquarist)


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## Rick_Lindsey (Aug 26, 2002)

Malawi_Junkie said:


> You could test your theory by taking a small peice of styro and see how much weight it takes to sink it.


Lets do a napkin calculation for a background for a standard 55gallon tank... lets call it 46" x 18". Lets assume you did 2 layers of 2" foam... but half of the front layer got chewed away by your carving (some of the back layer too, but lets just assume that the amount of foam chewed away was equal to half of the front layer).

46"x18"x2" + (46"x18"x2")/2 = 2592 cubic inches. at 231 cubic inches per gallon, that background displaces 11.22 gallons of water, at 8.34 gallons per pound = 93.5 pounds.

So if the styrofoam background plus it's weights weigh in at 93.5 pounds... it will be neutrally buoyant. Presumably you want it to sink, so call it 100 pounds . You'd have to embed a barbell in it, and that's just for a standard 55... if your plywood tank is bigger...

-Rick (The armchair aquarist)


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## alanvickiuk (Jun 14, 2009)

how about using egg crate for the back with an attached base and supperted corners

attaching real rocks with zip ties then filling in the gaps with expanding foam then using epoxy resin and covering in sand kinda like this

http://reefcentral.com/forums/showthrea ... id=1300282

im thinking of doing something like this

could also use lava rock and dark sand


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## Mcdaphnia (Dec 16, 2003)

Rick_Lindsey said:


> How about sand-casting a solid concrete background? Or if that's too heavy for you, mix perlite or somesuch with the concrete to make it less dense.
> 
> -Rick (the armchair aquarist)


A good mix with cement is peat moss. The peat helps counter the alkalinity of the cement and makes the resulting concrete lighter. Gardeners make this and call it hypertufa.

http://toolgirl.magruffman.com/downloads/pdfs/01_20.pdf

It can be used to make outdoor or indoor flower pots and watering troughs for animals.


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## corbz (Jul 30, 2010)

not sure if this helps but this how i did mine. i gotta 3'ft tank, made my BG outta styro. i never had to silicone it to the back of the tank, cos wanted to be able to take it out later on when i dont like it anymore. if you can just silicone or somehow glue a ledge (same thickness as back piece of your BG, mines 1 inch) to the top of your tank, like what the lid normally sits on, make your BG fit underneath it. then depending on how much gravel / sand etc you have in there, i got bout 2 inches push that up against it and it should hold itself in there, well mine does and has for couple months now. cant see why it wouldnt work for a bigger tank also...


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## bntbrl (Apr 23, 2009)

Im going to try that hypertufa McDaphnia. I have to go get a bag of portland but I needed to get it for some other stuff anyway. I never would have thought about adding peat to it.


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## bntbrl (Apr 23, 2009)

So I was thinking about that peat and cement mixture. Instead of using styro as a backing whats the difference between just siliconing the styro rock blanks to the glass and then laying the tank on its back and either pouring cement over it or using Drylock? Would laying rocks in the back and then setting concrete mix in to about a 1/4 or 1/2 inch thick work also? I would not want tto take the background out later.


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## Mcdaphnia (Dec 16, 2003)

bntbrl said:


> .... I would not want to take the background out later.


Can I save that and quote you later? :lol:
. . . . . . . . . . . . . . . . . . . . . . . . . . . 
The best laid schemes o' Mice an' Men, 
Gang aft agley, 
An' lea'e us nought but grief an' pain, 
For promis'd joy!


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## Ant-man (Jul 23, 2010)

I have read on another post that some made the styro back and carved out as nuch styro as they coukd to the concret and filled it in with mortar to make it less boyant, then just held it down with clamps. I'm wounder if anyone has done the styro backround and tried to melt the stry out of it and then filled it back in with concrete. Has anyone ever done this???


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## bntbrl (Apr 23, 2009)

Id try it with a ten gallon or 20 gallon. They are readily available to me and cheap. I have several tanks that I want to experiment on at the moment. I wouldnt want to try it on a 100 gallons or something expensive ro something Id want to change lol.


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