I have not posted for a while now so you don't know me very well, but I think I can help out here.
FYI, I was a painting contractor for 35 years and now have a lot to do with aquarium backgrounds.
Two things we are concerned about, adhesion and toxicity.
Adhesion : With the products made these days adhesion is the best it has ever been, however, always use the best quality paint you can, usually meaning the more expensive. Always clean the surface to be painted very well, you know, no dust, dirt, grease, etc. The rougher the surface the better. And let the paint cure before harsh use.
Toxicity: Use either acrylic, latex, or epoxy paint for interior use. With the EPA rules these days, manufactures have to formulate interior paint to be non-toxic. The problem with exterior paint is the addition of fungicides to keep moss and mildew at bay.
Cure time: What does that mean ? The liquid in paint is called the vehicle. Cured paint is when all the vehicle is evaporated and completely gone. Just because paint is dry to the touch does not mean the vehicle is gone. 30 days is the average cure time for paint to cure completely, but after 2 weeks most of the vehicle is gone.
Also, when paint has completely cured to has it's best adhesion possible.
FYI, I happen to know that certain aquarium background manufacturer's have used interior acrylic latex paint for years with no problems.
Please don't ask me who.
One last thing, the thinner the coat of paint the better. A second coat takes a lot longer to cure because you trap the vehicle in the first coat.
I could go on with this, but maybe I will start a thread dedicated to paint sometime.
Hope I have shed a little light on the subject.
Chip
