# Green Dust algae (pics)



## killacross (Oct 15, 2009)

no...that is the line that the light is hitting your tank...and apparently you have too much of it.

basically...it travels from your bulbs in your hood out at an angle down and toward your glass...and when it contacts the glass it hits from that point of intersection down. the reason its a strip is because at a certain depth, you lose the intensity so it cant sustain the algae growth.

I had the same problem in a 10gallon shrimp tank because of the shape of a DIY hood. but once I moved the bulbs for more spread out light...it went away.

1) reduce amount of light or 
2) reduce photoperiod &
3) clean your tank!

should clean up on its own after that.


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## hbosman (Oct 5, 2006)

I was constantly having to clean Green Dust Algae from the bottom 2/3's of the front glass. Just how the light hits the glass from the light fixture. I went to running 2 bulbs for 10 hours with a 2 bulb 5 hour noon burst and still was getting GDA. I then set the noon burst to 4 hours and now no GDA, yeehaa. I dose dry ferts with a lean EI method and 50 % water changes per week. I used to fight Black Beard Algae on the plumbing and silicone until I went from 1/3 water change to 50 % water change. It's funny how a seamingly minor change can make such a difference. It's just a matter of finding that balance I suppose and lighting and water changes are the easiest things to change.


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## latchdan (Sep 7, 2007)

I left the algae growing because i was told if you let it grow for a couple weeks then scrap it off it wont come back because the algae goes through its life cycle.


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## hbosman (Oct 5, 2006)

I've read that as well but, I was never that fortunate.


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## latchdan (Sep 7, 2007)

I reduced the light to 8 hrs from 10 already, its 2X55 PC light for AH supply with a DIY hood over a glass top. On a 37 gallon


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## hbosman (Oct 5, 2006)

That's alot of light. 

I tried 8 hours as well (all 4 bulbs) and it helped a little but not much so, I went back to 10 hours. I then went to the 10 hours with 2 bulbs and a 5 hour burst (the other two bulbs). I was still scraping GDA off of the glass. I just decided last week to reduce the burst to 4 hours, cleaned the glass and no GDA has come back. My Glosso now looks like it is reaching so, I will tweak the burst back up in 15minute increments to find the sweet spot of minimal GDA and low growing Glosso. 

Maybe you could try raising the lighting somehow by one or two inches and see if it has any effect. I read somewhere that lighting intensity reduces by inverse square of the distance. If anything, it will change the angle that the light hits the glass. It might be worth a try.

Lighting is probably the easiest thing to change since fert dosing and CO2 is generally dosed in excess of what the plants need. And algae can thrive on much less fertilization.


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