Thanks for the replies. I bought it from a guy who had previously bought it from another guy who i've met and i'm sure imported F1's etc from the states, all seemed very Kosha anyway. What i did notice is that the guy i bought him off had him in a fairly small tank of about 180 litres and he was a yellow colour and about 4.5" when i bought him. He went in my 500 litre and grew massively over the course of about 5 months, like no cichlid i've had before. He's now about 9" at a push, and much more orange. The lights are pretty poor in that tank, and don't really do him justice. My thoughts are that because he's F1 or F2, he's better quality that the mass bred you buy in the fish stores that often don't really grow, and that's why he grew so well. He now permanently shares a tank of about 240litres with a school of 12 congo tetras which he ignores and a featherfin squeaker that he bosses about quite a bit (but the squeaker has an escape cave if it gets too heavy!).