# soft green algae on leaves



## upikabu (Sep 2, 2005)

Hi, 

I'm having a recurring problem in my 23g tank (2wpg for 10 hrs, pressurized CO2, EI fert regimen) with soft green algae infesting the leaf surface of my hygrophila corymbosa "stricta". It started to occur when I left on vacation for 2 weeks (turned the CO2 off and reduced light duration to 8 hrs during), but still occurring after I switched back to original routine & weekly water changes. I can remove it easily by wiping the leaves, but in a few days they would reappear again. I also notice that after wiping it off there are transparent areas on the leaves where the algae was (the algae blocks off the light?). It doesn't look like BGA (not slimy, lighter green color). At first I thought it might be GDA since I'm currently having GDA problem on my glass, but it's not powder-looking. 

Any idea what causes this algae and how to make it go away permanently? I've had the stricta in the tank for almost a year and they grow like mad, but this is the first time I've seen this type of algae on them. It also doesn't appear on any other plants in the tank. I have 3 otos in the tank and thought they would take care of this stuff, but it doesn't look like they're eating it. Maybe they're just too fat (or I need more otos). 

Thanks in advance for any advice!
Cheers


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## hoppycalif (Apr 7, 2005)

I am in the last stage of conquering my GDA infestation now. 18 days ago, right after I cleaned the tank thoroughly, GDA began again to grow on the glass. I left it alone, neglecting everything except feeding fish, fertilizing and CO2. As it got really dense on the glass I was able to see that all of the plants also had a green fuzz coating on the leaves. I left that alone too. Now, the glass is mostly clear, with just a few patches of old GDA being eaten by my now very big pond snails. But, the amazing thing is that the green fuzz is gone too. Apparently it was GDA too, and all of the colony went thru the life cycle together. The next critical part is, will it come back as soon as I finally do another cleanup? If not, this is a great method for clearing out that stuff.


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## Fiki (Apr 16, 2006)

The question is what shall we do in tanks w/o very big pond snails? BTW, I'm quite sure that some photo of this algae could help a lot...

Regards.
Fiki


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## upikabu (Sep 2, 2005)

Hi Hoppy,

Does the green fuzz on your leaves look like GDA? Mine isn't - more like soft green patches. When I left the GDA on glass alone for 2 weeks, it became a dark green goo. But the algae on the leaves remained the same colour/appearance during the same period. I mentioned in a recent GDA thread that my GDA came back after leaving it alone for 2 weeks and then wiping it off. I left it alone again for 10 days but yesterday I got sick of it and used a lot of paper towel to wipe it off along with a 75% water change. I also wiped off the green algae on the leaves. 

I've reduced the lighting period to 8 hrs and installed a quick filter on a powerhead in the hope that it will trap any remaining free-floating GDA. We'll see if the GDA and/or green algae comes back again. (crossing my fingers)

Thanks!


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## hoppycalif (Apr 7, 2005)

When I had the green fuzz I couldn't see it well enough to tell if it looked much like the GDA. It arrived with the GDA, grew big with the GDA and seems to have left with the GDA. The problem is that I didn't know that GDA grows on plants.

I didn't have any big pond snails either until this started. My tiny ones grew to 3/4 inch long on their feast of GDA! Now I worry that I need to remove a lot of them or they will die, generate ammonia and start another algae bloom.


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## upikabu (Sep 2, 2005)

Thanks. My green algae also arrived around the same time as the GDA, so you're probably right that they are either the same thing or at least related.


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