Black background

[Jack golden]

I recently scraped off the blue paint off of my tank and repainted it black

 

[Schniz]

I know some people prefer a background that gives more depth but I use black poster board on the back of all my tanks to make everything in the tank stand out more.

 

[Toiletcar]

Looks good. I use black too, but you can’t tell because of all the algae lol.