i have been running 250 watt radiums for the past say 4 months. the bulbs i bought where used prior. my question is to 250/400 watt halide users is.. should i screen my tank for initial break in? if i change them out without shading tank will i burn corals ? should i switch out just one , then the next a couple weeks after ? lights are kept 10 inchs from water. any insight would be greatly appreciated. thanks