Electric blue cichlids- is it ok to keep one or should I keep them in pairs?

[Shovad]

How wide is the tank? Column tanks tend to be tall and narrow so have less swimming room than a rectangular tank.

Height
25 IN
Width
13.75 IN
Length
13.75 IN

 

[Essjay]

With that width, you are very limited as to what fish you can keep. Even the smallest fish usually need a swimming length of 18 inches. You might get away with chili rasboras, which are suitable for your pH.