Photo period

[Spectorman]

I am interested in photo periods. I know this is kind of a beaten horse issue but,I think it's always a great refresher.
The last 2 years I have been using 2 Kessil A360's and T5 ATI combination. I get color and shimmer. Plus the advantages of both types of lightning.
Photoperiod seems to be a bone of contention for many aquarists. My photo period is for an extended period of time but my max is short. I am reading people with 6 hours of photoperiod are experiencing amazing growth with less light. Has anyone found this the case?

 

[brett559]

I run my whites/blues for 6 hours, then my blues only for 2. Corals are really doing well.

 

[Spectorman]

Nice.

 

[mcgyvr]

Yes.. In general 6 hours of light is sufficient..

 

[Spectorman]

So,let me ask what should otherwise be an easy question.
My photo period is 6am till 11 at night. But,...my Kessil's are programmed at 6am all blue at 5℅, ramping up all day until 5pm when they're at 50℅ color 85℅ intensity for an hour then ramping down to "0" around 11. At 530 my T5's turn on until 10 while the Kessils are at peak. Too much light?

 

[mcgyvr]

So you just have the blues on low till 5 (essentially a "moonlight") .. Then turn on colors and t5 for 6 or 5 1/2 hours.. ?
Thats fine really...

 

[Spectorman]

Well,they ramp up to peak out at 50℅color (50℅w50%b) and 85℅ intensity. Plus the T5's. It's making me question my own techniques.lol. this discussion in particular.

 

[rjjr1963]

Too much light will light will slow coral growth.

 

[Ron Reefman]

Tough to speak to too much or not enough light intensity without PAR reading, especially with a mix of fixtures that most other reefers wouldn't have.

As for photo period, the zooxanthellae need 5 to 7 hours of good intense (PAR of 200) light to do photosynthesis. A longer photo period doesn't help the coral, but it doesn't hurt it either... unless it gets to be so much that the dark period is too short (like 6 hours).