The size shouldn't limit you on being able to use the foam, but I would bet it will cost quite a bit. I haven't tried using foam with acrylic before, but I am sure others here have. The only problem with it I can think of would be mold releases. If the acrylic has any mold release chemicals in it, they will leach out over time and cause the foam to release. But being that it was a fish tank, I would assume they didn't use mold releases to make it because they are probably toxic to the fish. Also being acrylic, you can always anchor any heavy branches to the background just by drilling holes in it and using screws. Just make sure you drill them above your desired water level to avoid leaks. If I was building a terrarium out of a tank like that thats exactly how I would do it. Separating the sections wouldn't be any different than a small terrarium, so look at some other threads here to see how people do it. You can always caulk a piece of plexi in as a divider.

{{gwi:568366}}

-DH

OK thats exactly what I was worried about. I didnt know if the foam would adhere to the acrylic well. Also I really dont want to drill into this tank WAY TOO EXPENSIVE to drill into. So lets say I do the foam method, which is the best foam to use? Also can it handle being submerged under water and having to hold some weight? I know that I will install pylons then spray the foam around it so that the foam is not holding up 400+ lbs.

I also understand since its fresh water stay away from any limetone type of rock that will make my H20 too hard, what I would like to know what light colored stone is out there that doesnt leech calcium?

For filtering purposes I was just going to use the 100gallon refugium that I had for the salt water set-up since I have the large sumps in the basement would those be of any use to me?

Thanks
Miko