Review on TORCHSTAR LED Aquarium Light: Ultra Bright Fish Tank Lighting with Adjustable Clip and Waterproof Design - Perfect for Freshwater Aquarium Plants and Indoor Water Gardens (Pack of 2) by Becky Chopra

I bought these lights as a possible replacement for a 55 gallon plastic tank. Although I haven't used them for this purpose, I have kept them for my 10 gallon quarantine tanks and they are more than enough. I would say they can easily and beautifully light up any tank that is less than 3ft long and 1ft wide. If you are longer you may need to install a second one to avoid blackout at the ends of the tank (if you place it in the middle). However, they are designed for rimless tanks! So while I did manage to get them on my plastic rimmed tank, they only went down a few millimeters and the clamp bolts never went down far enough to be usable. So you're in place, the plastic is snug against the plastic. However, they are light enough that you don't have to worry about them falling into the tank on their own.