Lighting = the tropics

[BeanAnimal]

Here is some in depth info if anybody really cares...
http://aslo.org/lo/toc/vol_6/issue_1/0024.pdf

Sam, while we are at it... instead of trying to explain reflection, refraction and the "critical angle" to you... I have also posted a link with a nice demonstration tool to play with. http://www.ps.missouri.edu/rickspage/refract/refraction.html I hope this will help you undertand why your not quite correct.

Assuming that you WERE correct, the light would still diminish as it approached the "cut off" point that you contend exists.

And lastly Sam, all of the light that strikes the surface of the water is not from a sinlge direct point source. A good deal of light is bounced around through our atmosphere and strikes the water and other objects at many different angles. The surface of the ocean is not flat and certainly not still. Light hits the water at a LOT of angles. Think shimmer lines Sam!

 

[Donw]

<a href=showthread.php?s=&postid=8466454#post8466454 target=_blank>Originally posted</a> by BeanAnimal
As far as sunrise and sunset data... that is readily available at NOAA and many other webstites. I already wrote the software for my PC based controller. It takes the longitude and latitude and calculates sunrise and sunset. I did not go as far as looking into the actual light levels for the different parts of the day... I am sure it is not linear with respect to time....

Bean

Mine already has all the lon/lat tables built in. Just enter the lon/lat and then pick a time zone.

Don

 

[BeanAnimal]

Don maybe one day when we both have time we can compare code or results just to see if we both come out with the same basic cycle!

I assume you set it up so that you could offset the time to match the desired local time?

 

[Donw]

<a href=showthread.php?s=&postid=8467363#post8467363 target=_blank>Originally posted</a> by BeanAnimal
Don maybe one day when we both have time we can compare code or results just to see if we both come out with the same basic cycle!

I assume you set it up so that you could offset the time to match the desired local time?

It comes that way all you need to do is enter the lon/lat for your city. Tell it what time zone your on and thats it. Its all in the firmware. So far its been pretty darn close.

Don

 

[BeanAnimal]

What are you using that already has this stuff built in? I struggled for hours writing the code to do mine! I have a user configurable number of dimmer steps between sunrise and MH coming on and the reverse at sunset. I also included code to raise and lower the halides! but have yet to finish it. I will be using Dallas 1wire and advance dimmable t5 ballasts for actinic sunrise and sunset.

 

[Donw]

<a href=showthread.php?s=&postid=8467640#post8467640 target=_blank>Originally posted</a> by BeanAnimal
What are you using that already has this stuff built in? I struggled for hours writing the code to do mine! I have a user configurable number of dimmer steps between sunrise and MH coming on and the reverse at sunset. I also included code to raise and lower the halides! but have yet to finish it. I will be using Dallas 1wire and advance dimmable t5 ballasts for actinic sunrise and sunset.

The Applied digital Ocelot. At this point I'm not using lon lat for my tank just household lighting. I have the controller raising and lowering the halides. It takes just over two hours to go from 8" above the water to 32" before and after the actual 8 hour photo period so a total of 12hrs per day with just halides. Once the halides hit 32" they are about as bright as real bright moon lights. So far I like the looks.

Don

 

[BeanAnimal]

I was aware that you were using the ocetlot but not that it did sunrise and sunset...

 

[awestruck]

The technology available to mimic Mother Nature is impressive. Also admirable is the concern for growth of plants and animals living in glass boxes. One of my points, however, is that I believe Mother Nature already has it figured out; thus, perhaps it is imperative, for reasons which we may or may not know, to provide photosynthesis and growth a resting period. For example, I completely appreciate acroholic's example of the plants' slow recovery rate (5-6 days) after one day of no lights.
But, maybe Mother Nature wants the plants to slow down for a few days. Additionally, having lights out over a tank completely may not be comparable to a cloudy/rainy day regarding lighting. Just some thoughts...

 

[samtheman]

A little Bean Dip.........

"So why bother with dusk diving? The answer is two fold: full on marine life drama played out on a spectacularly lit stage. Hollywood filmmakers call the last hour of daylight the golden hour when the low angle of the sun and the quality of light make even the most mundane subjects glow with beauty. Underwater the golden hour creates beautiful light patterns at the surface, but refraction stops most of the light from penetrating far. The result is a juxtaposition of warm dancing beams slicing through dark water: a fittingly dramatic backdrop upon which to catch a glimpse of the reefs best behaviour. "

 

[Donw]

<a href=showthread.php?s=&postid=8470217#post8470217 target=_blank>Originally posted</a> by awestruck
Additionally, having lights out over a tank completely may not be comparable to a cloudy/rainy day regarding lighting. Just some thoughts...

I tend to agree here. I think this is probably the biggest reason most people reject the entire idea. Most dont have a way to simulate dawn and dusk and simply turn off/on bulbs from a single point light source is not going to do it.

Don

 

[BeanAnimal]

Sam.... stop while you are ahead please. You do this thread after thread.

The light levels underwater will rise and fall with sunrise and sunset... PERIOD. Nobody is argueing that the level has a 100% linear relationship with anything.

BTW
You may want to re-read the quote you posted.... it contradicts your initial point other than using the worfd refraction... a concept you obviousley do not understand.

Bean

 

[samtheman]

<a href=showthread.php?s=&postid=8473267#post8473267 target=_blank>Originally posted</a> by BeanAnimal
Sam.... stop while you are ahead please. You do this thread after thread.

The light levels underwater will rise and fall with sunrise and sunset... PERIOD. Nobody is argueing that the level has a 100% linear relationship with anything.

BTW
You may want to re-read the quote you posted.... it contradicts your initial point other than using the worfd refraction... a concept you obviousley do not understand.

Bean

How can I stop when I am ahead?

 

[BeanAnimal]

Heh?

Sam you said that sunrise and sunset have no effect under water. I said you have no idea what you are talking about and have shown you two scientific sources that show you are wrong.

You have supplied nothing but a divers observation that sunset is not as pretty underwater as it is on the surface.

So let me say this again. Sam as usual, you are wrong and nothing more than an uninformed smartass. So that we are clear here. Light levels underwater change as the light levels striking the water change.

If you don't understand that, then this conversation is far above your level of understanding. If you want to have a civil conversation about that, then we can continue. If you feel the need to interject smartass comments... then don't bother.

The stop while you were ahead comment was a polite way of saying "stop before you make more of an *** of yourself". It in no way meant that your contention was correct.

Bean

 

[awestruck]

samtheman--there is a reason that humans have one mouth and two ears.

 

[Ryanqk]

you wouldnt replicate a hurricane or other storm in your tank even though they happen occasionally, so why replicate a cloudy day? might as well optimize your light to be bright and have good growth rates

 

[awestruck]

Very good point Ryanqk, thanx for responding.

 

[BeanAnimal]

Not only that are tanks ARE NOT the same as a small piece of the ocean. Other than lighting differences, we have oxygen and chemistry differences, pressure differences, and a whole host of other measurable parameters that make our little eco systems much different than mother nature. It may be that trying to get the lighting and lunar cycles close will help coral spawning and make fish more comfortable... it may be that it makes no difference. I do know that the effect is appealing to me I also know that bringing the lights up gradually keeps my fish calm. When they go from dark to bright instantly... they kinds freak out for a few minutes.

 

[awestruck]

I know what you mean BeanAnimal--since my lighting isn't considered sophisticated I always start with turning on one of living room lights (I don't even have lunar lights yet) and give the fish and corals an hour or so to wake up. I hope that by doing even that my animals aren't totally whacked by too much bright light too quickly.

 

[GSMguy]

<a href=showthread.php?s=&postid=8444256#post8444256 target=_blank>Originally posted</a> by Acroholic
You know what...I have been reading numerous threads lately where someone believes he/she will better serve the tank environment by changing lighting on/off, or spectrum change etc. etc. to simulate more natural lighting conditions, IE cloudy days vs. sunny days etc.
After being involved in Hydroponics for numerous years, I have come to one conclusion. STABILITY & CONSISTENCY are the main factors in maximum growth and health of specimens propagated! Especially after growing multiple generations from the same genetic mother, showing even more growth and better health and more final product after each generation kept in exacting conditions.
A temp swing or a light outage will show a definite decrease in the quantity of final product...this IS quantitive!
We did however change light spectrum....using MH for growth till flowering and changing to High Pressure Sodium Bulbs thru the flowering process. And did have to change light cycle (less light during the day) to induce flowering. But once flowering was induced we upped the light cycle back to 18 hrs a day.
I firmly believe that by keeping a steady and consistent lighting schedule (which will also help keep our temp. consistent) will benefit our corals in the best possible healthy environment. This is of course if extreme growth and health are your main priorities.

Maybe I cannot compare the two.....I would be interested to hear more about this.

i want to know what you were growning

 

[awestruck]

Wanted to add one thought: when I initially posted this thread it was in no way a criticism of doing or not doing something correctly. It was curiosity--you know, I wonder if...or, what about that... And as always, peace.