Background

i vote black

 

It's an aesthetic choice mainly (I like black as well) although I've seen some studies that have shown that a background adhered to the tank glass actually keeps more light in the tank giving you better performance from your lights.

Aside from painting you can use this stuff called SeaView Gel (google it) which you can use to stick black or blue aquarium backgrounds directly to the glass, helps prevent bubbles etc from forming on the background.

 

It depends on the color of your fish. P ersonally i like black, but if you have something like a niger trigger you want to show then blue would be better.

 

I'm torn between blue and black .
On my brackish water tank it's black but I can change it. For my new DT reef I plan to get thin semi-translucent colors (so some light from the fuge can bleed though...should look cool)@ the plasic retail store near me and change at will...oh and will get a mirrored background too. For the QT tank I'm starting along with the 46 bowfront I will leave it clear due to location(so we can see all sides.

 

I used a light blue spray paint because I read somewhere that the lighter color reflects more light for your corals and what not... Makes since technically but I wasn't thinking about the algae and crap. I wish I didn't go with a light color and now that my tank is full, i can't exactly change it right now. But painting is the way to go, you don't get salt creep or water marks between your background and glass.

 

Whatever color u do, u should use vinyl....

 

Black

 

You can also try something like sheet-goods auto / limo / residential window tint. It comes in varying colors / opacity. Thats what i did and it looks nice with the t5 lights on.

My only regret was not knowing about that background gel stuff that someone mentioned here in an earlier post.

However, my next tank may very well have tint on it again with the gel this time to get rid of wrinkles / air bubbles.

 

I like royal blue. And the seaview WORKS!!
Aquarium Backgrounds: SeaView Gel Background Adhesive and Sealant from Seaview Inc.

 

black makes a very striking background if your gonna take pics
Blue is also cool for a more realistic underwater feel
currently I have a blue roman ruins scene thats held to the back of the tank with a bit of vasaline - use a scraper to work out the air bubbles and the effect is like the background is actually in the water.