Need advice on Styrofoam backdrop creation

[JeffDenver]

I am trying to make my own custom background for a 29 gallon tank.

I am kind of nervous because After visiting sites like these:

http://www.aquaticplantcentral.com/f...styrofoam.html
http://www.thekrib.com/TankHardware/janne.html
http://folk.ntnu.no/foksen/Aquascaping.htm

I learned that styrofoam is inert and wont react with water. But some of these people have used latex paint in the contruction of their backdrops. I went to the hardware store, and the sales guy was somewhat horrified that I would even consider using latex paint for a submerged backdrop. He said it was a bad idea and that it would most certainly alter my water chemistry and kill my fish.

The tutorials also suggest using epoxy, but the hardware store guy also seems to think that this will react with the water in a bad way, even when completely dry.

So I am wondering if anyone on here has ever actually done something like this before. It's a really neat idea, but I dont want to risk killing my fish.

Are there different types of Latex and epoxy, and if so, what type do I need to use that will be aquarium safe?

[An t-iasg]

I really can't answer your question about different types of latex and epoxy -- but we just painted out house with latex paint. The paintbrushes washed out quite easily in just running tap water.

I have seen threads here of people painting the tank itself (the back glass on the outside) with blue or black spray paint in a can.

[roka64]

Latex will dry and be water proof. There are some types of epoxy that will work underwater. I would check with a few LFS in your area. Hopefully some one will pop in and be of better help.....

[Sicklid]

Exterior latex, like silicone II, has mold/mildewcides that will poison everything. I would not use latex at all because even when cured it is porous, and when left underwater it will absorb water and become rubbery again, most likely lifting off. It is not meant for continuous contact with water... It would have to be coated with a clear epoxy to stay safe in a tank... but for that I would not use latex, I would use artists acrylics which are very similar, but a little more inert and not apt to lift from the chemicals in the epoxy resin.

Really, the best thing is to use epoxy resin with some sand sprinkled on it to knock down the shine. Once algae starts to grow it really does not matter what color or how detailed the paint is anyway. I don't care what anyone says, nobody can clean these backgrounds till they are algae free, so let it grow! It looks natural that way... I just did mine in portland cement because I keep hard water cichlids that don't mind the alkaline nature of the limestone leaching into the water column.

[Plowboy91]

I would imagine that the correct epoxy would be better than latex...I just resealed several parts of my tank and when I was trying to find a sealant that wasn't as expensive as Aquarium Sealant I stumbled upon latex sealant which specifically stated on the label "not for aquarium use". I ended up using aquarium sealant. Once epoxy is cured it has gone through a chemical reaction and should be safe. Plus there are many types so I'm sure there is one for your needs.

[cccapt]

Many people have used HandiFoam from Lowes or HomeDepot for the inside backs. It comes in whitish/yellow and black. I've seen pic of both and they sprinkled some sand over the foam while it was still wet. It actually looked pretty nice, but these were in reef tanks. Dunno how it would look in a fw tank.