# Does green water cure algae problems?



## Raymond S. (Dec 29, 2012)

I'll relate an experience/w it.
I had a 10g tank under a window. All was fine for about a year.
Then one day I noticed a slight green tint to the water. Should have
said earlier that it got direct dunlight from about 8 A.M. till 11 A.M.
Then the green began to thicken. I read on here that you can "let it run it's course" and iyt will die off. So I just left it alone waiting for it to disappear. 4 months later it apparently had "run it's course" and did disappear on it's own. The fish(2) acted as if they never knew it had been dark in there. OK since you asked "HOW DARK WAS IT ?" LOL...
I could place my hand in the tank and could not see it till it was 3/4 inch from the glass.
But now that you mention it, after it disappeared, the tank was crystal clean of algae for a couple of weeks. And I was surprized that none of the plants looked any worse for the time which they had little light in there.


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## laconic (Oct 7, 2013)

My guess would be that what you did was similar to a blackout. The algae on the plant died because it was not getting sunlight in your pea-soup-like fish bowl.


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## g4search (Aug 10, 2014)

That's the wrong idea here. You can keep the plant for 5 days in complete darkness and the algae are still attached to it in the end. No cleaning there. You can do the experiment. 

Also, if it was due to a "blackout" then the _euglena_ should die as well, shouldn't it?


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## plantbrain (Dec 15, 2003)

g4search said:


> That's the wrong idea here. You can keep the plant for 5 days in complete darkness and the algae are still attached to it in the end. No cleaning there. You can do the experiment.
> 
> Also, if it was due to a "blackout" then the _euglena_ should die as well, shouldn't it?


Green water is NOT Euglena, Egulena is very easy to ID, Green water is very tough. 

We refer to Green water often as LTRGT. Little tiny round green things. 
Many just go to the DNA to figure out the type/species. 

As far as other algae, Green water will selectively remove light spectra, and other species of algae and plants "know" if it's from another plant/algae and not just something like tannins or wood, rock, poor angel of sunlight etc. 

Many species of algae will sporulate, have a lifecycle change that's not pesky. under such conditions. 

Overall, focus on plant health, not algae.
That was your original goal, do not lose sight of that. 
Then algae are not much of an issue thereafter. 
Most species of algae are good to show where you have gone wrong with plant horticulture. 
They are test kits saying what you did wrong.

GW is common in new tanks and with higher light.
Once bacteria settles in, it's rarely an issue. But you have to kill what is there and established typically, you cannot water change them away, UV and micron filtration are the most effective removal methods. 

Toss a jobe stick into water and add sunlight. Works most of the time. Good for filter feeding cultures etc, clam and mussel folks, maybe coral folks looking for algae to feed.


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## g4search (Aug 10, 2014)

*will green water remove BBA and other algae?*

Hi Tom,
I really appreciate your reply here, but I am afraid you misunderstood my post. Perhaps that's my fault.



plantbrain said:


> Green water is NOT Euglena, Egulena is very easy to ID, Green water is very tough.
> 
> We refer to Green water often as LTRGT. Little tiny round green things.
> Many just go to the DNA to figure out the type/species.


Frankly, I don't know what my green water is composed of at this time, but from the infos I found, I came to the conclusion that green water was mainly Euglena. 
I have a light microscope available in the office, so I have decided to take a look next week at a sample of my green water (unfortunately a camera can not be attached to the microscope). 



plantbrain said:


> As far as other algae, Green water will selectively remove light spectra, and other species of algae and plants "know" if it's from another plant/algae and not just something like tannins or wood, rock, poor angel of sunlight etc.
> 
> Many species of algae will sporulate, have a lifecycle change that's not pesky. under such conditions.


I think that the 'selective removal of light spectra' is not at issue here. It may actually be a factor, but there is something else going on. When you look at the pictures above, you will find that the algae on the plant actually disappeared!
When you take an algae-infested plant and keep it in complete darkeness for five or more days, the plant may look bad but the algae are still attached to it. Even when you treat algae on plants with either Excel or H2O2, they will turn red, but still stay attached to the plant for a couple of days, before they eventually disappear.
I feel the plants that I tossed into the green water bowl lost their algae rather quickly (wish I had monitored it). The _ludwigia_ are floating in my green water bowl for about a month now. They are completely algae-free and look rather healthy in my opinion. Perhaps they could even be replanted.
So why did the algae disappear?



plantbrain said:


> Overall, focus on plant health, not algae.
> That was your original goal, do not lose sight of that.
> Then algae are not much of an issue thereafter.
> Most species of algae are good to show where you have gone wrong with plant horticulture.
> ...


Thank you for reminding me to keep my eyes on the ball, that is to grow healthy plants. I am trying, but I just have never been able to do what you do. 
I had actually an algae-free tank for about half a year, but then, with the loss of CO2 for just 3 days, all hell broke lose. Except for the substrate, I had algae growing everywhere and I have been unable to get rid of them since.

Thanks again for your reply.


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## Biotope (Aug 30, 2014)

Hey there! I'm really not sure but I think it's due to the competition of nutrients? BBA and the other types of algae are considered "lower life form" while your bacopa and green water are considered slightly "higher life forms". Thus green water outcompetes the BBA causing them to die off while the bacopa and green water are larger and thus have more "reserve energy" to continue surviving? If in that sense it might explain why BBA dies off but green water and the plants do not. Also as the BBA dies off between the green water and the bacopa, the bacopa is the "higher life form" thus in that sense in the competition for nutrients the bacopa outcompetes the greenwater and thus the greenwater eventually fades leaving a tank without algae or greenwater


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