Theory Behind DUSK/DAWN

[dnguyen1]

Hey guys, I know the dusk/dawn effect helps emulate the nature of reefs. But is it a HUGE benefit (other than aesthetics) for the fish/corals?

Also curious what timing people have on their actinics vs. the 10K etc.

 

[Sk8r]

First of all, humanly speaking, aesthetics: your corals will glow different colors under actinic.
Secondly, it is a hunting period for some of your fishes, like mandys, scooters, etc.
Thirdly, you can't keep the mh on too long (I run mine about 7-8 hours) without your tank getting too hot and it sunburning some specimens. Your coral's zooxanthellae appreciate it, but in moderation.
Fourthly, the actinic does have energy to contribute to your corals, and it continues to provide it, in mild degrees, after the mh has gone out. You'll also see your corals begin to fold up or extend tentacles for the night, fish begin to seek their sleeping spots---this provides a quiet-down period for the reef, a changing of the guard for the night.
I don't run moonlights. I have my actinics on 12 hours, with the mh pretty well centered at 7 hours in the middle. Since the reef really doesn't care WHEN it gets this cycle, I arrange it to have the mh off during prime tv hours.

 

[dnguyen1]

Awesome, thanks for the feedback sk8r what about the DAWN period? My fish are always awake in the morning, just from the sunlight creeping through...

 

[Mikey Donuts]

One of the other benefits of dusk/dawn is that it helps to prevent startling your fish. Even though they're awake, a sudden blast of MH light will definitely stress them out. The same goes for killing the lights. The fish will get very stressed if you suddenly turn out the lights.

 

[Nano Chris]

It also helps mimic the natural environment like at the real coral reefs.

 

[snorvich]

And, if you have pairs, dusk is often their normal mating time. Especially if you have dimming lights.

 

[dartmti]

Does some form of light have to be on at night so the tank isn't in complete darkness? (Like moonlights)
Or do the fish like complete darkness?

Thanks

 

[dartmti]

Bump!

 

[otrlynn]

<a href=showthread.php?s=&postid=12981203#post12981203 target=_blank>Originally posted</a> by dartmti
Does some form of light have to be on at night so the tank isn't in complete darkness? (Like moonlights)
Or do the fish like complete darkness?

Thanks

From what I have read on here, the moonlights are primarily for the viewing pleasure of the tank owner. No problem with complete darkness for the fish.

 

[Harry_Fish]

I run 6 T5 Bulbs with dimmable ballast on a curve as in nature.

It is intererting to watch the changes in the corals and the
behavior in the fish as the light changes throughout the day.

 

[dartmti]

thanks!

 

[drparker]

I have read that when adding a new nem to the tank to keep moonlights on for a few weeks. So the fish can see it and don't acidently become a late night meal. Not sure if it really helps but it sounds good.

 

[snorvich]

Yes I don't know if that is necessary but certainly not a bad idea.