Theory Behind DUSK/DAWN

dnguyen1 · 07/19/2008, 09:17 AM

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 · 07/19/2008, 09:28 AM

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 · 07/19/2008, 11:01 AM

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 · 07/19/2008, 11:06 AM

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 · 07/19/2008, 02:52 PM

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

snorvich · 07/19/2008, 04:00 PM

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

dartmti · 07/19/2008, 04:13 PM

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 · 07/20/2008, 12:09 AM

Bump!

otrlynn · 07/20/2008, 06:54 AM

Quote:

Originally posted 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 · 07/20/2008, 08:01 AM

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 · 07/20/2008, 01:18 PM

thanks!

drparker · 07/20/2008, 01:43 PM

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 · 07/20/2008, 03:15 PM

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

07/19/2008, 09:17 AM	#1
dnguyen1 Will work for fish Join Date: Jun 2008 Posts: 910	Theory Behind DUSK/DAWN 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. __________________ Trying to keep the tank clean ONE DAY AT A TIME. Current Tank Info: 50g cube

07/19/2008, 09:28 AM	#2
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	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. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

07/19/2008, 11:01 AM	#3
dnguyen1 Will work for fish Join Date: Jun 2008 Posts: 910	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... __________________ Trying to keep the tank clean ONE DAY AT A TIME. Current Tank Info: 50g cube

07/19/2008, 11:06 AM	#4
Mikey Donuts Premium Member Join Date: Sep 2005 Location: Suffolk, UK Posts: 933	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. __________________ - Mike Current Tank Info: 150g mixed reef, 90g Seahorse

07/19/2008, 02:52 PM	#5
Nano Chris Registered Member Join Date: Apr 2006 Location: Baltimore, MD Posts: 2,758	It also helps mimic the natural environment like at the real coral reefs. __________________ Chris ------- 34 Gallon Red Sea Max 130! Setup (Just got back into the hobby) Current Tank Info: 34 Gallon RedSeaMax!

07/19/2008, 04:00 PM	#6
snorvich Team RC member Join Date: Aug 2005 Location: Outlander Posts: 40,953 Blog Entries: 46	And, if you have pairs, dusk is often their normal mating time. Especially if you have dimming lights. __________________ Warmest regards, ~Steve~

07/19/2008, 04:13 PM	#7
dartmti Registered Member Join Date: Jul 2008 Location: NC and TN Posts: 184	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

07/20/2008, 12:09 AM	#8
dartmti Registered Member Join Date: Jul 2008 Location: NC and TN Posts: 184	Bump!

07/20/2008, 08:01 AM	#10
Harry_Fish Moved On Join Date: Aug 2007 Location: Liverpool, NY Posts: 1,461	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.

07/20/2008, 01:18 PM	#11
dartmti Registered Member Join Date: Jul 2008 Location: NC and TN Posts: 184	thanks!

07/20/2008, 01:43 PM	#12
drparker Registered Member Join Date: Feb 2006 Location: Palatine, IL Posts: 2,652	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.

07/20/2008, 03:15 PM	#13
snorvich Team RC member Join Date: Aug 2005 Location: Outlander Posts: 40,953 Blog Entries: 46	Yes I don't know if that is necessary but certainly not a bad idea. __________________ Warmest regards, ~Steve~