# How safe is Styrofoam under substrate ?



## Crispino L Ramos

It is safe (inert material used for making drinking cups and food plates), glue it on the glass to prevent from floating. I have seen it done at a reputable privately owned LFS. One of the store owners built a riparium with a water fall. He used styrofoam to build a terrace which served as the waterfall. He covered the styrofoam with pond liner and had plants cascade along the liner to hide it.


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## jreich

i would hate to see the glue thats holding the foam give way. there would be fish, water, and substrate shot out of the tank like a rocket. why not juse rocks or bricks? cheap and much easyier then having to deal with glueing something as boyant as foam to the bottom of your tank.


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## Oreo

Styrofoam works just fine. I've probably got just as much foam as water in my planted aquarium.

With that said, the real trick is finding a good glue that will bond well to both glass and styrofoam (without melting the foam.) Allow me to suggest Gorilla Glue. It was the best I could find without looking up some industrial supplier of some adhesive noone has ever heard of.

Gluing the foam in the tank is far superior to using rocks or other weights. Glue will hold just fine if you use the right stuff.


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## OverStocked

It is a trick to get it to stay down long term. You risk a lot having it under EVERYTHING. That means EVERYTHING will come up when it does. Do not underestimate the buoyancy of Styrofoam.


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## Leester

The reefers use plastic fluorescent egg crate diffuser, zip ties or krazy glue and screen. They use it make caves and standoffs and things to lessen the use of expensive base live rock. It cuts easy and and can be formed into many different shapes. Lowes, HD, Ace etc. Many uses! sorry no pics


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## Lycosa

Another option is to use the expandable spray foam in a can. It sticks no problem and can be cut and sanded to whatever shape you want. A lot of false DIY backgrounds are made using that stuff.


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## F22

I would personally opt for the egg crate, I use it for nearly everything in the shop, I used to have all my coral sitting on it


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## Mr BrownThumb

*Aw cr*p*



over_stocked said:


> It is a trick to get it to stay down long term. You risk a lot having it under EVERYTHING. That means EVERYTHING will come up when it does. Do not underestimate the buoyancy of Styrofoam.


I'm dry-starting my 60 gallon. I have an 8" x 8" square of styrofoam underneath appoximately 20 -25 lbs of sand and Seiryu stone. I put it there to help maintain the slope in my scape (click my journal link to see). Is that going to be a problem when i flood the tank?


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## OverStocked

Mr BrownThumb said:


> I'm dry-starting my 60 gallon. I have an 8" x 8" square of styrofoam underneath appoximately 20 -25 lbs of sand and Seiryu stone. I put it there to help maintain the slope in my scape (click my journal link to see). Is that going to be a problem when i flood the tank?


I wouldn't do it. Especially if it isn't glued down very firmly


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## Mr BrownThumb

over_stocked said:


> I wouldn't do it. Especially if it isn't glued down very firmly


It's not glued down at all. The weight won't hold it down?


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## OverStocked

Trouble is if the weight shifts it could shoot out, and the styro will rocket out of tank, hit lights, etc all while maybe cracking tank with rocks. 

People often underestimate the bouyancy of styro.


> I wouldn't do it. Especially if it isn't glued down very firmly
> 
> 
> 
> It's not glued down at all. The weight won't hold it down?
Click to expand...


Sent from my Droid using Tapatalk


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## chad320

they use blocks of styrofoam to float large metal docks along the river. Good luck. Why dont you use plexiglass and silicone?


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## Mr BrownThumb

chad320 said:


> they use blocks of styrofoam to float large metal docks along the river. Good luck. Why dont you use plexiglass and silicone?


 great


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## CichlidFL.

Ive heard people reccomend a layer of styrofoam under the substrate to prevent rocs from creating pressure poits or somthing allong those lines on the bottom of the tank, anyone got any opinions on that?


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## OverStocked

CichlidFL. said:


> Ive heard people reccomend a layer of styrofoam under the substrate to prevent rocs from creating pressure poits or somthing allong those lines on the bottom of the tank, anyone got any opinions on that?


I think it is a bad idea. For the reasons posted above. I have yet to find a tank bottom cracked by these "pressure" spots. Can you find one for me?


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## chad320

It would have to be a thin layer, like a 1/4" and some heavy rocks on it. You shouldnt have to worry about pressure points if you have substrate under the rocks.


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