the way you tan a Golden is not very humane and I personally would never do it but if you must know the proper way is by putting it in a tank that has 4 sides all white, sides, bottom and back all white. Then lower the water level so its only about 4-5"s more then the height of his body so if the Aro is 4" tall then make the water 8" and then do tanning regiment with tanning lights on top and on the front. There is no real guarantee that he will cross the gold over his back or cover his head but that is your best chance. To be honest the only way to get a golden Aro with gold all over is to buy a 24K Gold Helmet. now im not sure where you live but in Canada they are over $2000 for babies but even at babies they have gold all over their bodies