Im not sure why people are recommending you start a reef tank with an Eclipse tank of ANY size. True, the light is 8 watts, but that is 8 watts of what? A 3500K bulb?
You will not sustain corals in that tank under that lighting, and the dense sponge/bio wheel will hold waste and nitrates like no other.
I have the Deco 3 kit. 18 watts of 10,000K 50/50 lights with a filter that turns the water over about 50x an hour. Yes, the corals have all doubled/tripled in size. But the light that is needed to sustain corals (IMO, 9 watts @ 10,000K) is too much light on what amounts to 1.5 gallons of water once all rock and corals are added.
I broke down my 3 gal because the tank size is simply too small for the light needed, and evaporation IS a problem. Some people will say evaporation isn't a problem with the lid on, but water/air exchange is a must to have a healthy tank.
I just upgraded the 3 gal to a 5.5 AGA. I have this tank at my office all day, so evaporation shouldn't be a problem. But after my experiences with a successful 3 gallon reef, I will tell you NO ONE should do a 3 gal unless #1 you have the proper lighting/filtration/amount of LR, and #2 you plan to break it down after 4 to 6 months.
Long story short, there is NO reason to do an Eclipse tank, since the Deco is cheap. And #2, do yourself a favor and start with 5 gallons or more. Once everything starts to grow, it is a pain to upgrade after the fact.
