A few months back, I saw someone use Black Waterfall Foam to create a background for their tank. It looked really nice.

So I thought I'd like to use some to camouflage caves in my tank, such as covering a slate cave for my pleco so the inside of the cave is what HE wants while the outside doesn't look like slate at all. Then I'd add plants on top which would make it all look even more natural.

I got a can and was about to try it when I read that any foam exposed to sunlight must be painted. Apparently, the UV from the sunlight decomposes the stuff.

So are the lights in a tank able to decompose the foam? Do I have to paint it? If so, what paint do I use?

Understand that this foam is 100% non-toxic once dried and is used to hold rocks in place for pond waterfalls. It is intended to be used with fish. But it's generally for ponds and not aquariums even though I know some people have used it in their tanks.

For those who have never heard of the stuff, here's a google search on it:

http://www.google.com/search?hl=en&s...ms&btnG=Search

And here's a page that offers some good information about it. It says. "Black Waterfall Foam is an expanding polyurethane foam that quickly seals gaps and spaces between rocks in ponds and waterfalls."

http://www.underwaterwarehouse.com/subcat916.html

My main question is whether I have to paint this stuff because the lights in my tank will break it down just like the UV light from the sun.

The mercury in the tubes produce UV light when it is excited by the current. The UV rays pass through the phosphorous coating in the tubing, which causes it to fluoresce thus producing the light we need for our plants. So you may want to coat the foam with some type of UV inhibitor.
Sorry, I should have given a warning about scientific content.

Don't you just hate people who give a long winded answer when just yes or no will work?

Oh, please, absolutely no apology for the scientific content. That is precisely the information I like to learn! I'm a bit of a geek in my heart.

So that answers the question of whether I should paint the foam or not. The answer is YES. I must paint it.

So what paint should I use? People use paint for their backgrounds so I know there's a type of paint that should be safe and effective.

Ummm... no, not really. I'm probably one of the most verbose posters on this site. So I'm not only the pot, but the kettle, too! Long-winded is my middle name!

I am very interested in this thread!
wouldn't uv rays be reduced by the water?
I can't find any good links to building under water cliffs/caves, river banks etc...
is it possible with this stuff?
I am very glad to have seen that this stuff is produced.
I keep mainly loaches and want to build a under water river bank of sorts with tons of caves. All the caves would have to be sloping down so the fish would not get stuck in them during water changes.

Just yesterday I was looking at an interesting tank journal on the SFBAAPS site where someone had made a cave out of the waterfall foam. He didn't paint it since the entire cave structure was then covered with Aquasoil. He also installed a red LED light in the cave so that he could see his apistos in the cave through the front of the tank. Apparently fish can't see red so the light doesn't bother them. He built the filter intake into the cave and put in a small micro pump that could be turned on to help flush out any detritus. It was in a 5 gallon tank and took up most of the bottom right side of the tank. The side with the cave and aquasoil sloped down to meet the white sand used on the left front side of the tank. Very creative.

I can't answer most of your questions which is why I'm asking questions myself. I'm surprised more people haven't latched onto this stuff which is one reason why I'm wanting more information on it. It's almost too good to be true, isn't it?

Hey Captain! Can you offer a link to that page? Maybe it's lurking in your browser history so you can find it again?

I'm also interested in how well the waterfall foam can attach rocks to each other for caves. We all know how poorly most things work to attach rocks to each other. But this stuff is designed to hold rocks in place. If it can create a good bond between two rocks, imagine how we can use it as a "glue" to make caves!

I'm also wanting to figure out how well it will attach to PVC pipe. Think loach caves! Give them the inside they want while we get the natural looking outside we want. (Of course, I'm talking about adding plants over the foam to finish the natural appearance.)

All I need to know is what I need to use to paint over it. What paint are people using when they create custom backgrounds? I would think that paint would work for what I'm trying to do.

Oh, and for anyone else who tries this stuff, be sure to read all the warnings. Not only is it highly flammable before its cured, but it is just about impossible to get it off your skin. So impervious gloves are a MUST.

On UV radiation from fluorescent lights, I found this on the GE website:


"Lamp manufacturers generally strive to minimize ultraviolet light (UV) radiation in all lamps used in general lighting applications.


The amount of UV produced by standard fluorescent lamps, such as those in your office, home, or school, is not hazardous and does not pose a major health concern. In fact, a paper by the National Electrical Manufacturers Association (NEMA) explores this subject in more detail. It cites a study in which it was determined that UV exposure from sitting indoors under fluorescent lights at typical office light levels for an eight-hour workday is equivalent to just over a minute of exposure to the sun in Washington, D.C. on a clear day in July.


Some applications require the absence of UV. To completely eliminate UV, we would recommend using CovRguard® shatter-resistant lamps. Where CovRguard is not available, UV sleeves or filters are also used to eliminate UV."

Using Great Stuff Spray foam insulation is very common in Salt water tanks to construct reefs, it will also work in fresh water but once its dried it is recommended you coat it with an Epoxy resin to seal it and protect it(Zap is a commonly used brand) Great stuff is Inert when dry, so nothing to leach just be sure to give it plenty of time to dry. Want a more Natural look? Coat it Down with Zap epoxy resin, then sprinkle DRY play sand over the resin and BOOM looks like a sandy river bed( or you can buy the fancy colored sand if you prefer) Oh and you may want to do it outside it kinda stinks! i would allow 48 hrs drying time just to be sure!

Vance is right about the Great Stuff in the can. It is inert and it is widely used with building vivariums for poison dart frogs (which are extremely sensitive to chemicals. I would imagine that it might be a real challenge to keep the stuff from floating though.

As to coloring it, I know I have seen where people use Krylon Fusion to paint spraybars and filter intakes. I would imagine that it is probably inert when dry, but don't quote me on that without verifying it for yourself.

When Salt water people do it they tend you use a ton of Base rock on a premade frame of Egg crate and fill in the gaps with great stuff cause yes it floats like mad! rocks would work a(flat rocks can be drilled and Zip tied to the egg crate then you simply cover the trimmed zip tie with great stuff and once you epoxy and apply sand you have a VERY natural looking set up!

I have Great Stuff already. I've thought of using it, but the color turns me off. The Black Waterfall Foam is pretty much the same thing, but black, and it appears it's much stronger (I've never heard of Great Stuff holding rocks together, but maybe it can?).

I'll look into using Zap or Krylon Fusion to spray over the waterfall foam. Since I intend to put plants over it, I may not even need anything. The plants may shade the stuff so much that whatever UV light that may be coming from my lights would be too little to make it matter.

I'm also wondering how long it takes for the waterfall foam to break down. Are we talking a month or a year? Makes a difference. Also, in what way does it break down? Get brittle and fall apart? Melt? I don't know. Maybe I can get some info from the company that makes the can I bought. It has a phone number on it.

I've seen the "covered in gravel, sand, whatever" look and have tried it myself, but to my eye, it's still to obvious what the piece really is. I'm hoping the expanding properties of the waterfall foam would distort the shape of whatever I'm using it on to the point the original items can no longer the detected.

I may play around with trying Great Stuff and paint since I have it on hand.