No lights for 3 days every couple of months works wonders!
 

I've been doing this for the last year now on my skimmerless 40 gallon mixed reef and the results have been positive. The tank is home to mostly LPS and soft corals with a few SPS. The first time I let my tank go dark this long was to combat dinos. Long after the dinos have gone I still do it because of the positive results I noticed.

I start the darkness period whenever I notice micro algae and diatoms building up on my glass and sand bed which typically takes 2 months or more to appear after each 3 day period of darkness. During the 2 months or so between each period of darkness I need to spend very little time with the mag cleaner and my sand stays pearly white. The tank does get a fair amount of indirect sun and many LPS corals open up during the day with out the lights. The fish remain active and feed normally.

The first day following the 3 day period only my actinics are used ~ then its back to a normal schedule. The visual results are similar to a water change. The tank is as crystal clear as can be and the corals respond with excellent polyp extension.

Today is the start of another 3 day cycle. I am going to post some pics of the tank a couple of days after the cycle is finished. I will also compare some tank pics with others taken back in Sept. and let you decide if you think it effects coral growth or not.

I don't know if anyone else practices this method of "purification" but it is now part of my husbandry after the results I have had.

Here is pic of the tank back in Sept:

http://img221.imageshack.us/img221/1934/sept0607cg0.jpg

Here is a link to a thread with more pics.

40 gallon mixed reef.

Very cool idea.... i may try this. It does make sense, as i'm sure many reefs go through cloudy periods of a few days here and there.

From IceCap:
I usually tell a panicked customer whose lights have failed that even the ocean has cloudy days. I may refer to this thread next time, to not just suffer through it, but to consider making it part of their routine.

Very nice and different looking reef tank.

Andy

I would have to go digging for the article since it was some time ago.
They stated that the avearage reef in tropical zones recieves an average of 80-95 days a year of unfiltered sunlight.

The rest of the time the sun is partly blocked or totally blocked by storm/rain clouds and on rare occasions volcanic dust and more often by dust clouds from Africa (depending on location).

So a few days of darkness or subdued lights such as actinics would actually be more natural then blasting them with a thousand watts 14 hours a day seven days a week year round.

Yep there are plenty of overcast days in the South Pacific and other regions. Then there is the monsoon season. I also run only actinics for a day every once and awhile.

ASH ~ Thank you for taking the time to comment and I appreciate the fact that you like my reef! It does look much better now as many of the upper frags have now grown to the top of the water column.

I have also done some experiments with my change water. I save it in a covered tub with a power head in case of emergencies. There were some zoo polyps, amphipods, nerite snails, and a micro star living in there for months. The zoo polyps were in there a few months before they turned completely transparent.

Other things I noticed ~ after a 3 day cycle a small patch bryopsis that I had became transparent. It was easy to tweeze and syphon off and it never came back.

omni2226 ~ That article sounds interesting. Since I order a fair amount of wild collected corals I have studied up a bit on many of many areas of marine life collection. These regions get quite a bit of rain fall and the islands are typically lush with plant life and cascading water falls. Do a google search on Micronesia or the Solomon Islands. Micronesia is especially fascinating IMO.

That is one peeerty tank! We had our "cottage cheese" removed from our ceilings and the tank had to be covered with a tarp for three days. I was so scared when I took that tarp off. What I found when the lights came on was that my tank never looked better! Now I leave my lights off for two days each month.

Cool, I'm going to try this too and see if I can kill the rest of HA I have, how about clams? I have 4 of them

This would be a good idea to remove cyano as well. I would do a large water change after the lights out period. If you see the algae disappear, it's going somewhere. It's turning back into phosphate and nitrate in your water. The water change would be a good way to remove this.

and to think of how much money you save on power....

Can you tell us a little about your filter setup? I am wondering if you have a refugium and if so, do you keep the lights out on that as well?

Like cristhiam, I am curious about the clams after 3 days of darknes?

Sounds like a cool idea. Corals definitely go days without sun, there are cloudy days :) Instead of running lights the same amount and time every day, maybe mixing the photo periods up could have a positive effect on corals?

wrong post

hmm...I'm having a pretty bad algae outbreak and I might try this and see how it works. :)

Thanks for the comments everyone!

Ritten Thanks! Its nice to see someone else doing this with good results.

cristhiam & mmj456 ~ My Deresa clam has no problems with the cycle. I don't think 3 days with-out light is the answer to an HA problem but the lack of light may make things easier for manual removal as the HA is weakened.

Questin ~ The only filter I have is an AquaClear HOB for running carbon. I do not have a fuge but do have wads of cheato growing behind my rock wall. Check out the thread linked to above for more info on my set-up.

msuzuki126 ~ Who knows but it does seem to mimic nature a bit more.

InvaderJim ~ A dark cycle may help with an algae problem but by no means is it going to be a cure. Micro algae appears to be effected most. The thing you will notice after the cycle is the increased clarity of your water.

LobsterOfJustice ~ Cyno will definitely disappear. How long it stays away is going to depend on other factors.

Bebo77 ~ I suppose on some larger systems you might save a few bucks here and there.

That's how I beat my HA problem way back.
Scrubbed rocks, and covered tank w/ sheet and no light for 3 days.
Then did what I needed to remove the nutrients.
That tank looks great Aqua.

i am looking to be on the starting point of a bubble algae breakout, do you think i should try this?

Ok I'm going for it the HA is already weak since I've been doing water changes and removing by hand, this is a good time for me to do it since I'll be home on the weekend and have some what more control over it. I'll post the outcome.

I don't know for sure, but I don't think this would help the bubble.
I had some HUGE ones growing hidden under rocks.
Emerald crab.
HA does work great though, especially when weak and doing what you need to rid the source.

I'm sure all animals, including clams, will be fine. Light is one of those long term needs, not short term.

On the trip from collection to holder to airport to west coast to holder to wholesale to retail to you, I'm sure they have endured much more than three days lightless.

God created clouds and so must we.
:)

But I have heard that our levels of lighting don't even provide the same amount of light that is present on the real reefs on a cloudy day. I'm not disagreeing with the results but...total tank darkness for three days in comparison to just a cloudy day in the tropics is not really a very valid comparison. Just a thought.

Dennis

Does this have any affect on your pH?

The tank is not in total darkness during the 3 day cycle. Its in a room that gets a lot of indirect sunlight. I agree though it is not a valid comparison. A lot depends on the type of corals you keep and what depths they are collected from.

kslick PH dips as it would any night but stays stable throughout the cycle.

I havent been on RC in a long time. Clicking on the first random thread I saw, you have the nicest tank I have seen in a long time. I love it. I will take your advice on the lighting thing too.