What is it

[Ninabobo]

Hi,
I see something on my aquarium wood. Anyone know what is it? Is that algae or fungus?
Thanks

 

[itiwhetu]

Looks like black beard algae

 

[Avel1896]

Hello,
Black beard algae or brush algae.
You should check this because very often seen in an imbalance (overfeeding, overpopulation, lighting, faulty filtration, ... ) or poor maintenance. It seems that a high level of nitrates is very often the cause (100mg/l). Phosphate level should also be checked.
This appearance can also be seen in a well-balanced tank when there is a significant difference between KH/GH.

 

[Sgooosh]

it looks pretty cool like a little black crystal lol

 

[Avel1896]

Yes but..................... from a distance