I've decided to change my photoperiod.

I've lengthened the amount of light my tank received per day. At the same time, I've reduced the amount of intensity (all lights on) my tank receives per day.

My old photoperiod was:

Bulb 1 and 2 on at 11am
Bulb 3 and 4 on at 12pm
Bulb 1 and 2 off at 7pm
Bulb 3 and 4 off at 8pm

This gave me 8 hours run time, per bulb, per day. The tank received 7 hours of intense light per day and a total of 9 hours of light per day.

My new photoperiod is:

Bulb 1 and 2 on at 10am
Bulb 3 and 4 on at 12pm
Bulb 1 and 2 off at 6pm
Bulb 3 and 4 off at 8pm

This will still give me 8 hours run time, per bulb, per day. Now the tank will recieve only 6 hours of intense light per day and a total of 10 hours of light per day.

The reason I changed my photoperiod is two-fold.

1. After looking at what other T5 users (entire web) are doing with their lighting schedule, most seem to agree that they have better coloration with a shorter intense lighting period. While these are purely observations by those users, I'm included to give it the ol' go ahead to see if my observations match theirs.

2. I wanted my lights to be on a bit earlier in the day in order to observe my tank. At the same time, I didn't want to increase bulb usage as 24 watt T5 bulbs are about $20 and each bulb's useful life span is only about 9-12 months.

In conclusion, I hope to have helped coloration of my corals while increasing the total time my lights are on per day. At the same time, I haven't increased the amount of time each individual bulb is turned on.

Questions for you...

1. What is your photoperiod?

2. Where can I find documentation, on T5 bulbs, showing the relationship between hours in use and spectrum/intensity loss.

Christopher