I have a Hamilton deluxe lighting hood that I recently did a light upgrade on. I have gone from 2x175 watt 10,000K to 2x400 watt 20,000K. I aclimated my tank and the corals looked much better and were going strong. I have recently, for the first time, experienced a rash of RTN. I am looking about at all items for possible cause. All the water checks out and I can see no cause. I have however noticed that the 1/8 inch plexy sheild that came with the hood is a bit burned and warped some from the increased heat. Also one bulb showes carbon charing at both ends of the inner capsule and appears less blue and intense. Would my 1/8 plexy offer enough UV protection and or might this one bulb be part of my RTN problem?