photoperiod/algae question

[scrapman]

In order to reduce the photoperiod, is it important to turn off both the daylight and the actinic? If i turn off only the daylight, is the actinic alone going to "feed" the algae growth?
Thanks

 

[tizzo]

Algae is a plant. A green plant, and green plants feed off of the red side of the light spectrum. A very low K rating, like bulbs that are 6500K, will induce algae growth. Actinics, being mostly the "BIV" side of the spectrum, will not aid the algae at all.
A higher K rated bulb is also beneficial for controlling algae, but the corals need the ROY side also for growth speed.
Do you already have algae or are you trying to prevent it?? If you already have it, which kind do you have?? A lot of factors should be considered when trying to reduce algae growth.

 

[donald]

Tizzo is on the right track.