Those led pendants can ONLY be hung and NEED to be at least 12" away from the water or u risk the chance of burning everything up due to too much light, 90degree optics are standard so if your tank is more then 14 inches deep look into bigger optics, i was gonna be led then decided t5 was the way to go, tommy . IMO t5s are the way to go if your unsure about leds. Beside im willing to put my money on it that in two years time well be able to pick up 120w dimmable cree led fixtures for around 100 120 bucks DOMESTIC