No Lights for 3 Days Every Couple of Months Works Wonders!

[Aquabucket]

Originally posted by washingtond
Did you monitor the PH and Oxygen levels in the tank during the dark period? If so did you see any drop? If not why do you think that they did not?

The PH droped the same way it does on any normal night but it remained stable through-out the blackout. The lowest my tank dropped was 7.9. It typically peaks @ 8.1 - 8.2 everyday. If you are worried about low PH you could always drip some kalk. I do not have any means to test O2 levels but I do run an air stone injected HOB during the black-out. Most other people run skimmers. There are plenty of ways to get more O2 into your tank if this is a concern.

[omni2226]

I am still trying to locate that article on the amount of unfiltered sunlight the average tropical reef recieves each year. If I remember right it is about 90 days.

I did stumble across this tidbit at Sea World. Note that it isnt so much the amount of light as it is water that is rich in nutrients and oxygen.
So with your skimmer or venturi powerhead going, and maintain feeding leaving the lights off for a day or two shouldnt hurt anything.
I will keep digging for that article....

. Habitat requirements.
1. Although various types of corals can be found from the water's surface to depths of 19,700 ft. (6,000 m), reef- building corals are generally found at depths of less than 150 ft (46 m), where sunlight penetrates. Because reef- building corals have a symbiotic relationship with a type of microscopic algae, sunlight is necessary for these corals to thrive and grow.

a. Reefs tend to grow faster in clear water. Clear water allows light to reach the symbiotic algae living within the coral polyp's tissue. Many scientists believe that the algae, called zooxanthellae, promote polyp calcification. See symbiosis for more information on this algae and its relationship with coral.

b. Light-absorbing adaptations enable some reef- building corals to live in dim blue light.

2. Reef-building corals require warm ocean temperatures (68 to 82 F, or 20 to 28 C). Warm water flows along the eastern shores of major land masses.

3. Reef development is generally more abundant in areas that are subject to strong wave action. Waves carry food, nutrients, and oxygen to the reef; distribute coral larvae; and prevent sediment from settling on the coral reef.

[Aquabucket]

Thanks for the info omni2226. Feel free to post more when you can.

[blue_eyes53813]

I have been fighting diatoms and blue/green algae for about 4 months now.. My tank is a brown slime mess. I got rid of it for about a month and just yesterday my whole tank was covered again. It is very very disheartening... Today actually in disgust and not wanting to see my tank ( before I even read this thread) I shut off the lights. That is how fed up I am.. The tank is 2 years old... Ive tried everything. increased water changes, less feedings, less light periods, better skimming, diatom filters, changed RO filters monthly (yea I go through alot of them). I was really worried without the lights my corals (a mix of sps and softies) would suffer. I have thousands of dollars into my tank.. The algae really takes away from the beauty. I am gonna try the 3 day no lights and see... I dont have anything else to try...

[saltman123]

[i]I am gonna try the 3 day no lights and see... I dont have anything else to try...

Good Luck. Definitely post back the status and if it helped.

[markzfishn1]

Does anyone who tried this have clams? It sounds like a great idea, but I'm not sure how well clams would do without light.

[jlynn427]

do you guys leave your refugium off as well. or should i leave that on its regular schedule?

[Aquabucket]

My Derasa clam never showed any stress at all.

As far as shutting off a fuge I don't have one but I do have plenty of cheato hidden behind my rock-work and it is also unaffected by the black-out.

[trae]

Wow, Nice tank!

[Old Yeller]

thanks for sharing

[Aquabucket]

Thanks!

Here are a couple of more recent pics:

[cbeitel]

I have been battleing Cyano and decided to try this.

WOW. All the Cyano was gone and the tank looked great. The water was clearer for sure and I had cyano on EVERYTHING. Rocks, sand, and it was killing off the coraline and macro.

Thanks for the Tip!!!!

By the way, I kept the fuge lights on, and did 1 day actinics followed by 2 days no lights except moons.

[diciple]

power company calls me when i turn off lights for two dayslol

[chinaman4u]

I tried this too! Shut off my lights for one full day(yesterday) and came home from work today(the second day), turned on VHO's at 6pm(normally on at 12pm) Will have halides back on tomorrow.

It works great!!! Got rid of my cyano! Tank crystal clear! I have a reverse photoperiod fuge that I left on. And it was raining all day and yesterday, so there wasn't much indirect lighting.

A++++ (before & after)

[tomasga]

I had a huge breakout of green hair algae. After months of fighting it with different critters and manual intervention I decided to turn the lights off. I left them off for a week as I was totally fed up and ready to tear down and start over, I saw no adverse affects on the coral, or life in the tank. 95% of the algae died and ended up in my filter which I replaced the pads on. I then started tunrning the lights on only for a few hours a day and now (2 weeks) almost all of the annoying algae has gone. YAY!

[PupChow]

Light is off for the 2nd day in a row in my tank. Battling Bryposis, will update.

[chris wright]

Im giving the idea a try as well. Im trying to stop recuring out breaks of cyano. Ive tried all other methods, but of course they dont work when fish are in the tank. Poor bugga's gotta eat to.

I dont have any corals (if you dont include a polyp that came on the live rock, likes lower light intensity anyway), so im going to leave my lights of for a longer period. Ill post my results in a few days as wel.

Chris.

[panther28]

Today is the second day my lights are off. Cyno is reducing at a good pace. Although fuge lights are on. This is by far the best way to fight an alage problem!

[salty55]

yup, my mind is made up! as of tonite my lights are going to be off for 3 days. i have been battling hair algae for a long time. nothing has gotten rid of it. this is the last step before i pull MY hair out.

[melev]

Tonight, my tank has been dark for three days. I can't wait to see how it looks tomorrow.

My skimmer seems to be pulling out just as much stuff as it normally does, so lighting doesn't seem to have any effect on the volume of DOCs in the water apparently.

[Tang Salad]

Originally posted by melev
so lighting doesn't seem to have any effect on the volume of DOCs in the water apparently.

Mightn't this technique even temporarily increase DOCs? If it works to kill algaes/diatoms, then those will release DOCs as they die. It seems maybe it'd be best to crank up skimming as this is being done?

[cbeitel]

Even Marc is on the "Lights Off" Band wagoon!

So far there have been ZERO ill effects. My PH was stable (But its always stable).

Hope you get the same results Marc!

[melev]

Originally posted by Tang Salad
Mightn't this technique even temporarily increase DOCs? If it works to kill algaes/diatoms, then those will release DOCs as they die. It seems maybe it'd be best to crank up skimming as this is being done?

I clean my skimmer daily so if there is something to pull out, it'll do it. What you said makes sense about the die-offs. Hmmm. Well maybe tonight it will pull out more muck than what I saw for the last 24 hours. I won't measure it, but it was worth thinking about.

Yeah, I thought the idea was a good one and decided I wanted to try it out myself. Gives me something to talk about.

[Tang Salad]

Yeah, now we're really getting some weight behind this!
(Not a fat joke, Marc )

I'll be trying it soon in an attempt to clear a little remaining nusiance macro algae. Problem is, I don't know if I can stand not seeing the tank for so long.

[Dejavu]

Originally posted by Tang Salad
Yeah, now we're really getting some weight behind this!
(Not a fat joke, Marc )

I'll be trying it soon in an attempt to clear a little remaining nusiance macro algae. Problem is, I don't know if I can stand not seeing the tank for so long.

I don't think I could take three days of not see my tank too.