For the DLI question, (inches of rain is a nice analogy, BTW) please keep in mind the relationship between the DLI and the saturation point of the livestock. I prefer a lower color temp appearance in my tank - more of a natural sunlight appearance instead of the Windex blue that has become prevalent nowadays - so I run a feeding period in the middle of the day. From 11 to 3, I ramp the lights to a higher peak (450-460 PAR), with an emphasis on the 430nM-470nM range. The 3 hours before and after the feeding period I run at a lower PAR (340 range) with more cyan, yellow, and a touch of red. It is a very effective way to get the aesthetics I want, while making sure that my higher requirement corals get the intensities they need. The challenge is keeping the feeding intensity at a level that the rate of photosynthesis doesn't create more oxygen than the corals are happy with (chronic photo-inhibition in the glossary above). Exceeding the saturation point but staying inside the dynamic inhibition range can have positive results on the appearance of the corals. Many pigments/carotenoids that give corals their great colors are present to protect the coral during natural periods of high-intensity light - think high noon in equatorial climes. If the corals' pigmentation starts to become pale/washed out, you've overshot.
As with any light changes, take it slow. Shallow water corals can deal with light levels that would fry captive propagated specimens, because they have grown up in such conditions. My feeding cycle was implemented over several months, and when I introduce new inhabitants, I back off the feeding period levels quite a bit, ramping back up over 30-45 days. Once corals have become accustomed to the high intensity period, they have no difficulty with the temporary reduction, where the new specimens have a real hard time if the return to higher intensities is too abrupt.
As with any light changes, take it slow. Shallow water corals can deal with light levels that would fry captive propagated specimens, because they have grown up in such conditions. My feeding cycle was implemented over several months, and when I introduce new inhabitants, I back off the feeding period levels quite a bit, ramping back up over 30-45 days. Once corals have become accustomed to the high intensity period, they have no difficulty with the temporary reduction, where the new specimens have a real hard time if the return to higher intensities is too abrupt.