Is 15 hours two long

[Devildoc]

I am currently running two razors and a ordc120 and run from 8am to 11pm blues run at 8 am ramping up to 80% which hits that at 2pm and stays at 80% till 6pm for the razors the dc120 is set at 75% from 8am to 11pm blues. the whites come on at 11am for the razors and hit a peak at 4 pm at 55% that runs to 6 pm then deems to off at 10 pm. the dc120 runs 55% from 11am to 10pm. would it be better to have everything power on at 2pm vs 8am? or as I've seen in some post I've read a 6,6,6,6 program has anyone used this? I've had this set up for over a year and haven't had much growth and I'm thinking the 15hr cycle is the problem..

 

[Mike J.]

Sunlight hours at the equator are 12 hours of daylight and 12 hours of darkness. This is what I emulate.

 

[mike007]

This Is confusing but I start my blues at 1 pm and then the whites come on at 2pm. The whites turn off at 10 pm and blues off at 11 pm. I have had great results with this cycle.

 

[Devildoc]

I guess that's why right around 4 pm my zoas and cloves start to close up.. thank you guys

 

[trido]

Ive been running my lights for 13 hours for about 8 years now. Peak lighting for only 7-10 depending on what I was running (400w MH, 250w MH , LED's etc)
Why do you need lights for 15 hours? Just like our brain. Plant life and almost every kind of life needs x amount of darkness and rest.

 

[Devildoc]

It wasn't that I need it my lights are all led.. and my razors have dusk to dawn effect and the power on and intensity builds and declines as the day goes on.. the dc120 I only dimmable.. its the blues that run 15 hours and my whites run 9 hours

 

[Ron Reefman]

With t5 or mh your on/off time was all potential grow time, although they only grow food for 4-6 hours. More than that is just for the benefit of your eyes. With leds it's different if you are doing sunrise and sunset. Low power settings give you lower PAR values and until you get up over about 100 to 125 PAR at 20" to 24" deep, no photosynthesis is taking place. So you just want to be sure you are getting 4-6 hours at high enough levels for photosynthesis to take place.

PAR meters used to be so you could avoid bleaching your corals, with long sunrise and sunset programs you can use it to be sure you are getting enough rather than too much.