Meter the hotter spots at the top of the water.
Based on your settings, devide the number by 65 and that is the approximate par.
I think you would want about 300- 400 par at the top of a 20in deep tank.
Based on an eight hour peak photo period.
BUT
If the nems are fine , they ARE fine.
I’m not a fan of making adjustments for a single species in a tank. If you bump the par , and have low light coral, it can cause probs.
If you have med and mixed , just go slow in acclimation of overall peak intensity.
But overall, I’d say what you have is likely fine.
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