Thy can be pricey but I use them on my emersed plants and I used to have a single bulb over a cube which worked well, brought out reds really well because it was warm white. They are worth a try though if you are handy with electronics or are friends with someone who is you can build a powerful easy to control DIY setup. If youre doing a small tank I say go for it and aim for 3500k-5500