Pretty simple question that I couldn't find an answer to. Can Green Phantom Plecos and Blue Phantom Plecos breed without any consequences?
As long as it's big enough. Like most plecs, there can be some aggression issues. I've had a L128 and L200, along with half a dozen other sp. in a 75 gallon with very little aggression after spots were claimed and everyone got used to each other.
Re-decorate to force the resident pleco to feel like he's in a new tank, that usually helps if it feels like it owns the tank.