sorry mate but my black cons get like that a lot its because someone crossed a black convict with a pink convict and instead of the body color changing the bar color changed. its not rare but it is amazing how its happens.
Glad it cleared up...yeah they will dig in it all day. I needed to re-set my rocks because the cons (and uaru) were digging under the rocks and tipping them...so I actually had to set the rocks right down on the bottom to avoid a rock falling on a digging fish.
Can't wait to see pics...do you like it better with the sand?
I'd like to put a 1/4'' layer of sand on top of my gravel sounds good cb...I hope that by you not rinsing it off that it does not harm your fish. I want to get a T-bar con they look pretty cool.