How long before an EBJD loses its black coloration? I purchased my Jack last summer at 3/4" and he is now about six inches. At what age do they become entirely "electric blue"?
Show us a picture, It may be as blue as it's going to get.
It could be water quality,Temperature, Tank mates, or food.
Also, My powder blue EBJDs keep a black base until I put them in a breeding environment.
Then he turns gold based. Really brings out the powder blue.
The fish to the right on the first picture,
And the fish to the left on the second picture are the same fish
Spike