Quick back story before my question. I've had my GTs since september. They are housed in a 75gal. I bought 8 of them to pair them off. Lost 2 due to aggrestion from another fish no long housed with them. The 6 lived well together for quite a awhile. About a month ago the largest male had developed a kok and grown much bigger than any of the others. He and the largest female laid eggs. I removed the other 4 terrors. Sadly none of the fry made it. Since then its like my tank has been going backwards, or at least pause. Female lost her color she is more tan now. The male has not grown at all and lost his kok. He had never really got his blue/green coloring and I've never understood that either. So did I hurt his development by removing other males? What can I do to fix this problem? My other tanks are thriving but these guys wont grow and color up!