So, I finally rented a PAR meter and mapped out my 75 shallow. The tank is 60"X18"DX16"H. My lighting consist of an Amazon, 4 bank T5 fixture and 2X48" OR3 blue+ LED bars. All lights are enclosed in a hood. The lights are approximately 8.5 inches off the waters surface. I have a map for the OR3s alone and two maps for OR3s plus two different T5 combos. The first is my original combo, OR3s plus 2Blue+ 1Coral+ and 1actinic, all ATI lamps. This combo was 1 year old at the time of measurement. The last mapping photo is the 2XOR3s plus with the new T5 combo, 3B+ 1C+ all ATI. You will see, that while the OR3s do not provide a lot of punch deeper in the tank (probably be reduced due to the angle) they definitely provide the blue LED pop! On the second map I quickly found out that 48 inch fixtures in a 5' tank drop off dramatically on the ends at the 8 inch height. Obviously the middle of the tank is receiving the most punch. Back in the day I ran MH with VHO actinics and was always a fan of the actinic bulbs, however; in this configuration it seemed to reduce PAR and be a waist of a lamp when compared to the blue+. I swapped out all of the bulbs to the new config, 2XOR3s plus the new T5 combo, 3B+ 1C+ all ATI and was surprised at the increase. On the third map I left the old measurement in a from-to type format so you can clearly see the increase. The PAR clearly still drops off dramatically on the ends with the center of the tank receiving the highest PAR.