Which Kessil light do I need for my reef tank?

As a general rule, 1 x A160WE Tuna Blue lights 45x45x45cm and 1 x A360WE Tuna Blue lights 60x60x60cm. 1 x A360X lights up to 90x60x60cm or 75x75x75cm, and an A360 Narrow lights 45x45x75cm. An AP700 lights up to 120x60x60cm, and the A80 Tuna Blue lights 35x35x35cm. All of the above would be adequate for coral growth over those areas, but for very light demanding situations, more lamps can be used.