This is the result of a single drop of Salmon oil hitting the surface of the lake, amazing isn't it? This phenomenon is called thin-film interference and happens when the angle of reflection varies as a light ray passes through different thickness of oil, the result is a rainbow-like colour pattern. However it does demonstrate the power of the stuff quiet well and how little you need to use. To much of anything is bad for you and fish oils are no different so a maximum of 5ml per kilo is plenty and a few drops in a stick mix or bag too for that matter. More is often less in carp fishing and knowing how much to use of anything is one of the biggest learning curves we go through. For me the rule is simple, always err on the side of caution and keep it simple. Cheers