[MrCrabs]

Hi, I have this dark green spots on the glass and wonder what type of algae/bacteria/whatever it is? And if I should remove it.

Thanks!

 

[Yukiharu]

Looks like BGA. Blue-Green algae isn't really algae; it's a photosynthetic bacteria.

 

[MrCrabs]

Looks like BGA. Blue-Green algae isn't really algae; it's a photosynthetic bacteria.

Thanks, how and should I get rid of it? I guess I can just scrub it?

Cheers

Update: I put some tape over it, hopefully it will die off without light.
How long should I keep in 'in the dark' ?

Cheers

 

[thedood]

Update: I put some tape over it, hopefully it will die off without light.
How long should I keep in 'in the dark' ?

Cheers

You did the right thing imo. Leave it on for a week or so, five days minimum.
I meant to say 3 - 5 days should do it.

 

[MrCrabs]

Next update:
After 7 days of darkness I did a sneak peak to see how it looks but the dark green stuff is still their (I don't see any change)

Is it supposed to disappear or will it stay there even if died off?

Thanks!

 

[dukydaf]

Yes it is BGA. I kept samples for 20+ days in darkness and they survived. Try to spot dose excel or h peroxide if only that area is affected. It will turn yellow / transparent once dead.

It is not a big problem but can act as a source for a bloom when the aquarium conditions are right, eg low nitrate.

Sent from my HTC One using Tapatalk

 

[Kathyy]

Taping the area only keeps ambient room light off the area, light travels through the tank pane as well. You could put an opaque plastic sheet between substrate and tank, that might work. Or push that plastic sheet, aka old credit card, between pane and substrate to roll the cyano back into darkness.

 

[dzega]

this is why i dont go with white substrates. you will always get junk and algae buildup there. scrape it off with credit card monthly would be my suggestion