# DO NOT USE great stuff



## Blackfeet

I saw an old thread and I needed to make people aware of the problems with spray foam insulation in the aquarium.

DO NOT USE "great stuff" spray foam in any environment where living things will constantly be exposed to it. It contains isocynate a molecule similar to cyanide which means I could break down into cyanide. It contains hydro fluorocarbon which break down into water soluble extremely corrosive acids. It contains polyol if I remember right this is a polyurethane solvent which gases off (never stops releasing this gas into the air or in this case water). In houses with very limited air flow through it into the living space it is much diluted. In an aquarium being such a closed environment this is asking for trouble


----------



## Chesh

I've never used this stuff, or considered anything like it - but thanks for taking the time to post up a warning to any searchers out there. Sounds like a dreadful thing to put into your tank!!!


----------



## bingo296

I have noticed this for the first time when i started my fishing hobby.
Thanks for keep us informed.


----------



## 1077

Why would this be used inside an aquarium I wonder?:hmm:


----------



## onefish2fish

ive made a few fake walls and fake rocks using this stuff along with some other things. i never had a problem with using it however my first one i used pond foam, which i believe is made by the same company. i didnt get the chance to test my great stuff yet but i have painted over it as well as sealed it in epoxy. 

im curious as to how you found this information?


----------



## 1077

onefish2fish said:


> ive made a few fake walls and fake rocks using this stuff along with some other things. i never had a problem with using it however my first one i used pond foam, which i believe is made by the same company. i didnt get the chance to test my great stuff yet but i have painted over it as well as sealed it in epoxy.
> 
> im curious as to how you found this information?


Ohh, I see.
I thought as much, but considering bouyancy, I had to ask.
Just figured it would be a pain to keep in place for long.


----------



## onefish2fish

1077 said:


> Ohh, I see.
> I thought as much, but considering bouyancy, I had to ask.
> Just figured it would be a pain to keep in place for long.


aquarium silicon before water ;-)


----------



## Blackfeet

First I am well acquainted with the hydro fluorocarbon stuff from my career as an auxiliary mechanic and oxygen clean training in subs in the Navy. I don't remember all the msds's (Material Safety Data Sheets) just the nasty and frequently used chemicals. My sense of smell for normal things has died down quite a bit but now I am much more sensitive to chemical smells. I noticed when I used spray foam in my old job that the smell never died down completely and it was stickier and messier than any other chemical I was exposed to, which made me wary. When I saw a post of someone planning to use it in an aquarium it sent up a red flag. I checked the manufacture website and got the chemicals I listed off their site. Keep in mind oil seeped into the ground is eventually broken down by bacterial enzymes just imagine what is possible in an aquarium with a living bio filter


----------

