From the pics, I can see open and happy frogspawn towards the edge of the tank, where it gets lower light. I would dial your light down to about 25% max on both channels to start. You can simply remove the optics to get more spread, I would have recommended the 24" fixture for a 36" long tank.
The frogspawn is alot lighter color on the sides like clear. I wish I got the the 24 but when we ordered the lights you only had the 16 inch controllable fixture... Than 2 weeks later you had different sizes, I love this fixture tho just trying to get it set up properly. Would my 2 sps be fine with just 25%