You are going to have to find a way to raise the light or dim it. I have the same light fixture over a 20 gallon tall. There was about 15-16" between the light and the substrate, and the light was way too bright. I had a diatom bloom right after getting my Ray 2. I had to use 2 layers of charcoal window screening (bought at Home Depot for $5) to lower the brightness, and it looks like it's working pretty well for me. My plants are growing well and the diatoms are going away.
It looks like you have a 15 gallon tank, so that means it's 12" high. Assuming your substrate is 2" deep, that means that there's only 12" between your substrate and light (mount raises the fixture about 2"). That puts you at 87 PAR at the substrate, which is well within the high light range. If you don't have pressurized CO2 in this tank, then you are going to have algae issues.
In the end, you are going to either have to raise the light or dim it somehow. If you decide to use window screening, then you are going to have to use at least 2 layers if not 3.