Okay so mainly the price difference in lights is because of demand lifespan and size, now say you have a 78.99 Chinese led vs. a marine orbit 156.99. The Marine orbit comes with moonlight more settings timer ect. Chinese LEDs come with a dimmer and on and off they only last about 3 years where as marine orbits may last up to 8 years. Full spectrum is something that you should have for corals but not 100 percent needed I don't have it and I grow corals, all it really affects is the way te colors are and how deep it goes into the water so if your tank is like a tall rectangle yeah you need a way more powerful light than a standard wide rectangle. Cubes are tricky so it takes a lot of testing to find the right light. Watts is what you need to worry about 66 gallons needs about a 275 watt led for Max coral growth on Lps and softies if you want any sps be prepared to see a 375 watt. A lot of light differ depending on you preferable I have Chinese LEDs that work fine for me, but others say not bright enough. I can grow health Lps and some sps so I'm not concerned. How many watts is your light?
