# A three day blackout actually works



## Johny_Dough

I have been struggling with Brown Algae and Hair Algae and I just blacked out my tank for some sick Discus. 2 days in no more visible Algae... So I do concure


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## mistergreen

Actually, Light is Key


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## plantbrain

For mild cases, it can work.
For more pervasive hair algae, no way
But some tweaking of the CO2 will generally address most issues with algae, that or reducing the light intensity and/or period.

Again, patience is the key with slow methodical adjustment of CO2.
Many are too impatient.

So they gas their fish or.....they have algae.


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## kcrossley

So how does one black out their tank? I take it you also discontinue Co2 injection as well, correct? What about regular fish feedings? Is there anything else you do to your tank during the black out period?


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## mistergreen

Cover the tank in black trash bags ( cut up into sheets) . It's ugly but easy and cheap. Make sure zero light comes in. 

Since there's no light, there's no point for ferts & CO2. Feed your fish if you like.

Some of your plants will start to die but they should bounce back when the lights are back on.

ps. Make sure to fix your lighting/CO2 that caused the algae in the first place, or you know what will happen.


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## brianS

I never cared much for the blackout periods. Tried it once, but common sense told me that there's no use for it when other measures can be used first.... light, co2 among the first. Patience of course being the foremost. In nature I don't believe there are any black out periods...at least not past dawn


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## agimlin

i had a green water issue and i did a 4 day black out and it all went away. . my java fern is suffering a bit but starting to make a come back.


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## DarkCobra

If you go the trash bag route, don't seal the top of the aquarium, or use an aerator. Oxygen still needs to get in!


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## wkndracer

Kept the HOB and air pump running. Added one of my AquaUV units with flow provided by a power head then bagged the tank for three days. Helping a friend start a low tech tank at his mothers home. She's on oxygen and nearly a shut in due to health issues. They didn't call when the problems started and I only found out after staghorn was covering 70% of everything. NO3 and PO4 had bottomed out and the tank was a mess. You can see the UV unit resting at the bottom left in the stand.









Bagged it after work on Tuesday afternoon and pulled the plastic off early Saturday morning. Rubbed leaves with my fingers and cut away what look the worst. Did a majority water change (left enough for the fish to swim) then dosed with trace, NO3, and PO4.

















I've been back twice letting 10 day's elapse between visits testing levels. Things are looking good and the blackout ended the algae while the plants are rebounding nicely.


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## Patriot

brianS said:


> I never cared much for the blackout periods. Tried it once, but common sense told me that there's no use for it when other measures can be used first.... light, co2 among the first. Patience of course being the foremost. In nature I don't believe there are any black out periods...at least not past dawn


your right, there are no black out periods in nature except at night. The amount of CO2 and ferts that occur in our tank also doesn't happen in nature by its self either and that's why we have to step in.


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## brianS

Patriot100% said:


> your right, there are no black out periods in nature except at night. The amount of CO2 and ferts that occur in our tank also doesn't happen in nature by its self either and that's why we have to step in.


I guess the point of my post was to state the fact that what we're doing is re-creating a process that does in fact occur in nature. CO2 does in fact occur, as photosynthesis... the two limiting factor that go into our tanks, light & CO2. The amount in nature is on a much greater scale than what we try to create in our tanks. As far as ferts go... that happens as well. What about the nutrient cycle that takes place? In other words; decaying matter is quickly broken down into nutrients and returned to the system. Again, on a much greater scale. Algae, if we just be patient enough, can be a learning experience all by itself. If we learn to control it, instead of trying to get rid of it then I find no use to wrap my tank up in a black garbage bag and turn everything off.


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## wkndracer

CO2 at the levels we keep in our systems RARELY could exist in nature.
The density of plants and fish along with the variety stuffed into the volume of our glass boxes exceeds most of what nature puts per gallon. Even with daily water changes I don't think many of us can match the dillution / change over rate. 
Aquariums please our tastes but aren't natural. (imo)


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## Patriot

I guess your both right I forgot about the humic acids and other goodies in the soils in nature. But I am pretty there is a higher concentration of CO2 in our tanks. Doesn't our atmosphere only have about .039% CO2?


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## whitepapagold

Funny to see the posters pontificating that a blackout is a bad solution...:tongue:

I had a BAD issue with BGA- cyanobacteria, not algae yeah, BUT man it did wonders for the BGA and reduced ALL the algaes in the tank. Its like an algae reset button.

It removed the BGA 100% and the plants are flourishing now 3 days later. New growrth on 70+%...

The blackout is a WONDERFUL method to address many issues. Its free. It wont hurt the plants (or at least 99%of the plants). It won't hurt the fish.

The only thing to do is a few water changes after the blackout to remove anything that got dumped into the water column after dying off. Plus clean the mechanical filters- by clean I mean rinse and remove detritus- dont leave them out or clean them 100%- you obviously want the bacteria.

I just used a micro fleece blanket for the blackout- they dont allow any light through! Love those synthetics!

But I will be doing a 72 hour blackout once a year just to clean up the tank from now on. The results have been drastic and successful to say the least.

BUT I do agree as far as a NASTY hair algae or BBA, you are NOT going to resolve the issue 100% with a blackout. Regardless, considering the potential results and cost- its well worth a try to see if it helps you get a handle on it.

I did see a reduction in BBA and a large reduction in hair algae. BUT they are both still there... You still need to resolve the core issue. I will say the BBA and hair algae are less prevalent though.

As for BGA- it cured the issue 100%. Literally 100%.


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