more information is really needed but a good guess at this one is high nutrients in the tank to begin with and adding a new bulb resulted in an algae bloom
The tank size is 24 x24 and ,connected to the Dt witch is lite by T5s and the old lite was a Phoenix 14k, there is very little of the red stuff in the dt but multiplied in the frag tank when I changed the light I have it 20" above the water as it's always bin and never have this problem
I would add some flow to the frag tank and display minimize feedings and look into some methods of nutrient control gfo reactor or carbon dosing I personally use vodka but how long do you run your lights?
Its a new light, and its alot stronger in the red spectrum than the 14k was, my guess was that your 14k was rather old also. No reason to use 10k anymore, should try to keep them in the 14-20k ranges, unless you just flat out don't like the look.