I've had blue and black on tanks and I prefer black.
10 Best Blue Websites in 2022 [+ Their Color Schemes]
Black Background Aquarium posted by Christopher Cunningham
ELEBOX Aquarium Background Blue Black Fish Tank
The 5 Best Live Sands for Reef Tanks
Black Background Aquarium posted by Christopher Cunningham
DIY Blue/Black Changable Background For Reef Tank Innovative
Page 2 Betta Fish T Shirt Design Images - Free Download on Freepik
ELEBOX Aquarium Background Blue Black Fish Tank Background Picture 2 Sides Fish Backdrop for Aquarium Wallpaper 20 x 48
Black, White, or Blue? Does The Color of Your Tank Matter
ELEBOX Aquarium Background Blue Black Fish Tank
10 Best Blue Websites in 2022 [+ Their Color Schemes]
ELEBOX Aquarium Background Blue Black Fish Tank
Aquarium Background Color - Bright or Dark?
Blue or black background: which looks better?
ELEBOX Aquarium Background Blue Black Fish Tank