Strange algae

[checkerboard]

recently, i went to a friend's place and he has an algae problem.

the following are the algae characteristics:

1) This algae ONLY sticks onto glass, does not stick to plants, his styrofoam backdrop or gravel.

2) it is soft in texture and can be easily clean off by just gently (no effort) scrubbing the glass.

3)perhaps, the most amazing thing is... after you clean off the glass totally. this algae infest the glass with the same intensity as before wiping off within 2 hours!

So, anyone out there knows what this kind of algae is and how to get rid of it.

unfortunately, i do not have his tank parameters.

regards!

[CT]

wat is the colour of this algae?

[Simon]

what colour and does it smell? slimy feeling?

[Plantbrain]

It's called green dust algae.

You scape off the algae and the zoospores simply float around till they re-attach, it's not NEW growth in 2 hours, it's just the spores reattaching.

You can scape and do a water change lightly vacuuming the gravel and water column.

Blackouts are sometimes effective.
Sometimes, afte repeated scapings/water changes etc, it goes away.

You can also hurt it by pulling the light away from the front of the glass etc.

Ankistodesmus is the genus.

Some tanks get it but well balanced tanks tend to have it disappear after awhile.

It's not harmful, but a nuisance.

Just make sure to scrub algae first, then do a large water change.

This removes all the algae spores that might attach back.

Regards,
Tom Barr