I went with 2 amare sp 400's and a single cobb led in between, to cover the 12' x 3' area. The single cobb should be good for seedlings and paphs i hope...with the catts under the amare's on both ends...plenty of light, no burnt spots yet....I do have a cat eldorado for the first time producing 2 buds under these leds...so happy for that, but it has only been 4 weeks...i hope it is an eldorado actually and fun to see the color variety if it is...