Lower intensity over time on effect

Question

I am very new when it comes to lighting, so bare with me. For an event, I am running a sequence of automated lighting. The idea I envision with the lights is that an "underwater" effect happens (I was able to make this). But as the scene goes deeper, the lights get darker (Less intensity). 
 I currently have the effect running 5 steps, lighting up certain lights randomly from 10 to 100 intensity. This gives me the desired look, but I am not too sure how to make it fade down in intensity over time. 
 
 Envisioned Sequence: 
 
 Bright underwater effect (near surface) 
 Scene is descending (Getting darker) 
 Reach bottom (Still subtle light, about 20% intensity max on effect) 
 
 All of this would happen over about a 14 second period. 
 How would I do this? 
 Thank you for any help!

eos moderator · Answer

This depends a bit on what type of effect you've used, but with all of them there's one way or another to make this happen. 
 You say you've used 5 steps, so I assume you've used a step-based effect. Did you use absolute values in the On column (i.e. 100, 50, or 20)? 
 In step-based (and absolute) effects you can use relative instructions: 
 The first step is a regular intensity The second step has the Background Intensity, i.e. the intensity the channel had without the effect The third step brings up the intensity by 10 points (i.e. from 50 to 60) The fourth step brings up the intensity by 20 percent (from 30 to 36) 
 2nd to 4th step react to the intensity you have stored in the cue. So if you're going from Cue 1 to Cue 2 in 14 seconds and in cue 2 you bring down the channels' intensities, you should get what you're looking for.