Sun is not real good for reef tanks, sounds crazy huh? When sun comes in through windows then hit the tank walls, normally an unwanted algae occurs. If it just a little bit of sun, then no big deal, but don't put the tank where it will receive a lot of sun. Heat can also be a issue, chillers are expensive and if your tank is put into the right room, not necessary, in my opinion. I do like a tank in a room that the whole family uses all the time, if people have to go out of their way to view the tank, after the initial infatuation wears off, only you will be enjoying the tank. If it is in a high traffic area, everyone enjoys it. Even with company, if you have to lead them out of the normal area's they will look at the tank and oo and ah, then go back to the party. Well these are just my opinions, but before you add a drop of water you have the time to pick the perfect place.