'cloudy days'

[Folta]

I was thinking about lights, and how light is in nature... and wondered if anyone ever leaves their lights off a day here or there, to kinda give their tank a 'break' from the light. Kinda like a cloudy day. I've only done it once (I was gone over a weekend, and didnt' have a timer at that point so I didn't turn the lights on for two days) and when I came back and turned on the lights, it looked as though the shrooms I had grew more than when I have the lights on every day. I guess I was most wondering if perhaps coral growth is anything like muscle growth in humans (ie. the light is like working out, its what 'stimulates' the growth, and the 'off' days are when the actual growth occurs).

 

Thoughts?

[Guest jamjam_77]

hmm interesting, maybe we should try that every once in awhile. Like you said it would have to be a day where I'm gone all day cause I love admiring the tank when I'm there.

[flowerseller]

Ahhhhh............... No.

 

 

Not that I've ever heard or read but........

 

it's a great guestion to ask this weekend!

I'm interested in similar photo period questions.

On my days off or days I have "meetings" and am actually home goofing off, I'll turn on my lights 5-6 hours earlier than the timers would. I figure I have this thing to look at so why not get stated looking and enjoying early.

[Folta]

Ah, well it was just a thought. I look in on my tank every day, so I suppose not seeing it for three days could also account for me actually noticing a difference.

 

I might try it anyway

[flowerseller]

Tim,

It's a pretty interesting thought, I'm going to ask this weekend and I'll let you know what is discussed. Like I said, sometimes my halides are on for 16-18 hrs.

I hear some people only run them for 6 hrs and have great color.

[emissary]

Also interesting is PAR readings on cloudy days (HOWARD??) ... IIRC they were higher than under ALL PCs, and some MHs.

[HowardofNOVA]

When I had the PAR Meter, I took several readings of light levels to get an idea what mother nature provided and was shocked at the readings.

 

Overcast Day around 5:30pm came up at 750

Hazy day was 785

Partly cloudy day when a heavy cloud blocked out the sun was still 550

When the cloud passed by and direct sun I got a reading of 1645

 

So even behind a heavy cloud, we are getting higher PAR readings then some of the best bulbs.

 

For those who got readings about 1500, don't get to excited because from my experience with the PAR Meter, when you put the probe on the glass of any lightbulb or with in 2-3" or less, the meter rang "1" meaning over 2000 on the readings, which meant that the probe was basically full of light.

 

Conclusion:

Turning the light off for a day in my opinion can do no wrong if only a day or two. This is actually a great way of killing algae blooms and besides, When it rains or heavy overcast skies, the corals are still kicking fine.

Howard

[Folta]

Thats very interesting, I would not have thought readings in nature would be that high (or rather, I would have figured with so many people using MH's, that it would be more in line with what Mother N was providing).

[traveller7]

Some of the settings on the old Solar Dimmers for VHO could be configured to simulate cloud cover. I don't remember really being able to tell when it was configured to be on :P

 

These days I run my mains on regular intervals, but do stagger the auxilary bank of lights in a manner that decreases lighting from time to time. The trigger for mine is heat though :P

[davelin315]

The zooxanthellae in corals require a break from photosynthesis. They function (at least from what I understand) in much the same way as chloroplasts in plants. They need daylight to absorb energy which they use during dormant times to create food for the corals. If you don't give them the light, they don't produce food, hence the reason why they strain and get so much larger under poor lighting conditions (for LPS and some softies). IMO, a shrunken but healthy looking coral is not struggling to obtain food. If you don't provide enough night time for them, they can't produce enough food to support the growth. Not having daylight during daylight hours has the same effect, not enough energy to convert sugars into a food source.

 

Oh, and I agree with what Howard said. If you think about it, a hazy day at the beach without suntan lotion will still give you a sunburn, but a day spent under your reef lights won't do the same and may not even give you a tan! If you really want to get the same effect as sunlight as far as the intensity, you're not going to ever come close with artificial lighting unless it's very intense and very close to the source. Just look at your tank on a day when sunlight shines in through the window and makes it look like your tank has no artificial lighting. The sunlight is that much more powerful to shade out your halides.

[fishface]

Yes, if mushrooms don't get enough light, they will stretch themselves to reach for it, and appear to have grown amazingly large in a short time. This is misleading as it can be mistaken for growth and happy parameters. There are those who are suggesting a "cloudy day" here and there is beneficial though. But this is for resting, not growth.

 

Make your judgments of their health based upon an average size with decent lighting over a few days time.

 

I'd like to design a system like Calfo did, where it was in a cool climate with natural sunlight. Dr. Mac has apparently done the same thing in his new place.

 

I think that natural sunlight would be a great improvement over existing lighting. I'd like to see whether my BTA gets it's bubbles back.

If I could, I'd put a tank up and use a solatube skylight or two, rather than and entire sunroom.

FF