Rookie Canna and Coco Grow. Lsd & Blue Mystic Led Style!

I ordered the same light and I wasn't quite sure I'd made a good choice, but then I ran into this and my faith was restored, killer work, it'll be cool to see u grow on a larger scale

Please help!! this is my second grow as I made a mess at my first one. Im growing 1 cheese and one Afghan and already they are both turning yellow as you can see in the images attached. Im trialling a 90w ufo led.

Any ideas why they are turning yellow and not growing much? they are about 9days in.

Cheers