Setting a lighting schedule

[acrylic_300]

What are some key things to look for when setting the schedule for lighting?

How do you know how much time is too much?
How can you tell if you need more time?

 

[o.c.d.]

Intence lighting tends to either overheat a tank and or cause excessive evaporation so some people run min hours. then simulate dusk and dawn with say less powerful lighting like 2 t5 bulbs.
I wouldn't go over 12hrs light 8 min. I've heard of people running as low a 3hr I think thats silly,saving bulb longevity vs coral growth . I run 14 bulb t5 3 seperate switches 4 bulb on 9am 7pm ,6bulbs and fans 10am 8pm, 4 bulb 11am 9pm. this is my attempt to simulate dusk to dawn.
To judge if more time is needed by coral expansion and growth. I watch my tank every day and if something is off A regment of tests insuses including lux meter or if you prefer par like most people PAR=1.53+(0.0111)Lux

 

[MCsaxmaster]

In nature reefs get 12 +/- ~0.5 hrs of light daily, depending on season and latitude. During the first and last hours of the day the light is relatively dim. During the middle 4 hrs (assuming no clouds, which isn't particularly realistic) the light is the brightest (depends on depth, water turbidity, etc.). During the other hours there is a large increase or decrease in light intensity (again, assuming no clouds).

This is what's available in nature, but may not be the most ideal photoperiod depending on what the goals are. A longer photoperiod may be preferable for encouraging faster growth in photosynthetic critters. Meibom et al., 2006 found more calcification in Stylophora pistillata with a longer photoperiod. I think 12 hrs/day is a fine baseline, and deviation from that is best done only for specific and well thought out reasons.

cj

 

[MJAnderson]

These is a discussion in the Coral Prop forum about running at 2 12 hour cycles (6hours on, 6 hours off, twice a day).

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1220656

 

[kydsexy]

do what makes you happy. 12+ hours will be too much and your corals might not be too happy. 8 may be too little, and not show growth. 10 always seems to work for me. I find that it's never a good idea to compare your tank to nature, because you can't simulate every aspect 100% try out times until you're satisfied

 

[MCsaxmaster]

Why would 12+ hrs be to much? You really think it is "never a good idea to compare your tank to nature?"

 

[jdkackley]

Other factors to consider are the style the lighting system, ie: MH, T5, PC and so on. Most MH systems use a short photo period for the halides like 6-8 hrs supplemented with 10-12 hrs of actinics. The intensity of the light setup is usually your determining factor. MH lights do there job in 6-8 hours, mainly because they are so intense. Any longer usually leads to algae problems or excessive heat. Not to mention higher energy bills.

 

[acrylic_300]

I should have mentioned my lighting. 880w vho and 452w of pc.
I also have ambient sunlight from numerous windows.

Iv'e been running 12 hrs for a year or so but I just boosted my lighting and changed out some blue bulbs for 10ks. Some of the zoas and mushrooms are looking "tired" by the end of the day. They actually perk up when the 10ks shut down.

My sps (various montiporas) are growing faster than the softies it seems...maybe once they start shading things the softies will perk up.

 

[jdkackley]

Acrylic_300, can you give me more specifics? Tank size, VHO photo period time, PC photo period time, bulb configuration, and what you are trying to prevent/accomplish ? Please be as specific as possible.

 

[acrylic_300]

At 7:30am the sun comes up through the east window very subdued.
At 10am 440w URI Super Actinic vho. [blueviolet]
At 10:15am 226w smartpac pc (10k/460nm). [white/bluegreen]
At 10:30am 226w dual daylight pc (10k/6500k). [white/yellow]
Also 10:30 am 440w URI Aquasun VHO (10k). [pinkish white]
At 1:00pm ambient sunlight through west window. [yelloworange]
At 4:00pm intense direct sunlight west window till 6:00pm.[Redorange]
At 7:00pm all sunlight subsides.
At 9:00pm only smartpac and URI Super Actinics (666w)
At 10:30pm only Super Actinics (440w)
At 11:00pm darkness till the sun comes up at 7:30am.

The vho's are being overdriven to 220w each. I figure I lose 30% efficiency doing this; however, I still calculate the lost wattage because of all the sunlight.

Because I'm not lighting the very ends of my 8' tank and the light is focused on a 7 foot long area...I estimate 5 watts per gallon. The lights are all 2 inches from the surface about 28 inches from the substrate. 75% of the light has to go through thick acrylic braces.


I'm not wanting my hard work on zoas and shrooms to wither away but at the same time I want the sps to grow rapidly to shade them.

 

[IndyReefMan]

Check out the archives from some of the past "tanks of the month". You may be able to find one that runs a similar set-up to you (eg- tank depth, bulb type, bulb wattage and color temperature). Most of the tanks of the month will show their photoperiod set-ups. You can then mimic what they are doing. If they've made "tank of the month", then there is a pretty good chance that they know what they are doing.

 

[kydsexy]

MCaxmaster, I guess that came out too strongly. You can never "simulate" nature. You can just get close. Nature has many more factors and less variance than a tank has. To compare the two is to say that a dentist is a doctor

 

[HBtank]

<a href=showthread.php?s=&postid=10952033#post10952033 target=_blank>Originally posted</a> by MCsaxmaster
Why would 12+ hrs be to much? You really think it is "never a good idea to compare your tank to nature?"

Wouldn't the consistancy of aquarium lighting systems be a fairly good reason to lower the duration (especially on intense setups) to less than 12 hours, since we rarely can relplicate the natural variation that would normally be seen on a 12-hour day, much less over a year..?

I guess I just do not see anything natural about the majority of the lighting systems we use, hence possibly deviating from the natural photoperiod and many high end setupds..