I strongly recommend these customizable LEDs. They come with control with tons of color adjustments and patterns. Very bright and cheap. You just order a roll and then go to Home Depot or lowes and get some white plastic Rain gutters. Glue these lights inside and boom you have a great led light fixture for $25. You say you have a 180 gallon. I'm assuming that's 6ft. One of these light rolls is 15 feet so you can wrap it up the gutter and back down for a double thick strip of LEDs that will be plenty bright. If you aren't happy with the brightness you can always order another roll and connect them together. I have spent $100s of dollars on LED fixtures in the past but no more these lights are great. I just spent $50 and have two 10 foot gutters painted black on top of my 500 gallon with 2 strips in each and it lights the tank up perfectly. The white light has a nice blue tint not yellow to it love it. And I use the blue lights for nighttime moonlight. Always fun to light the tank up Red or green every once in awhile though lol