# What color is GSA?



## Jlanders001 (Mar 31, 2009)

Is GSA a very dark almost black/charcoal grey? That's the type of algae that is plaguing my tank right now. It grows on plant leaves and substrate, but not on glass. It produces oxygen bubbles that stays on its surface almost constantly.

Any ideas of how to combat this? Am I dosing too much of something do you think? I dose five types of Flourish items from Seachem.

Phosphorus
Nitrogen
Potassium
Iron
Comprehensive supplement

Thanks,

JTL


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## Newt (Apr 1, 2004)

GSA = green spot algae. It usually grows on glass and is green and very hard to scrape off. It can grow on plants and look grayish but I've only seen this in pictures.

Can you post a picture?


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## Jlanders001 (Mar 31, 2009)

On substrate:










On a Sword:










On Anacharis:









Any special cures for this type?


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## rich815 (Jun 27, 2007)

This might be BGA or GDA. Is it slimy or powdery and easy to run off?


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## Jlanders001 (Mar 31, 2009)

More slimy than powdery. Forms small "sheets" sometimes. Not real easy to rub off, but it will rub off leaves with a bit of effort.

I've tried plant safe algaecide and I am running a small UV unit, but it does not seem to be going away at all.


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## crystalview (Mar 9, 2008)

There are a couple of things you can do. If you are not against excel then you could try spot treating. It would then turn black. If it clado I am not sure, Here are pic's of algae. I would try a 3 day complete black out. Your fish will be ok and this will kill most. If it is GDA then you leave it alone an it will go through it's cycle (may take a bit). Balance is the key in lights and fertz. How long lights are on what wattage and how much fertz along with WC's. Do you use CO2? Do you have a lot of fish or to few plants? The post below are short and easy to understand. Comes with lots of pics and what is needed. We have all been here.

http://www.gwapa.org/articles/algae/

http://www.theplantedtank.co.uk/algae.htm

http://www.aquariumalgae.blogspot.com/

http://www.plantedtank.net/forums/algae/79205-gda-do-nothing-seriously.html

http://www.plantedtank.net/forums/algae/86621-gda-do-something-seriously.html

http://www.aquaticplantcentral.com/forumapc/algae/3806-flourish-excel-got-rid-all-my.html


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## Newt (Apr 1, 2004)

I think you have Blue Green Algae. Does the tank have a manky odor?
Becareful as it contains hepatotoxins (liver).
Dose with maracyn or other antibiotic.
Check nutrient levels. Is your PO4 very high? This usually shows up in 'polluted' tank water and incorrect lighting spectrum. Are the lights old?


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## vancat (Nov 5, 2004)

yes, it's BGA or cyanobacteria-
use erythromycin.


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