Bought two. 20 inches for 10 gallons and 24 inches for 20 gallons high. Both give off a good amount of light for a planted aquarium in low light as described. In fact, with medium light plants you could probably grow twice as much, although I would suggest using Planted+ instead. You could probably grow some medium-light plants in higher areas. Don't expect to use a lot of red, though. Without more light, they just won't color the way you want them to. All in all, these lights are worth buying for a low-tech setup. For those who prefer a high-tech setup and more demanding crops, upgrade to Planted+ or higher.
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