Howdy PeterTan! Several manufacturers have LED lights now... there is a company running a banner here on site that has good units.
I have a GalaxyHydro 165 watt LED on my saltwater aquarium and so far I'm very happy with it. considering they specialize in hydroponics/grow lights and not reef tank lighting, I imagine their grow lights are pretty damn good and affordable. Amazon has thousands of LED growlights to choose from, even small bars or flexible strips for unique set-ups.
I am not sure where you are, last month I bought this led grow light, my plants seem to like it! https://www.amazon.com/dp/B01NCVWFUE