Bacterial bloom

[turtlehead]

How long does a bacteria bloom usually last?

[Simon]

depends on your tank, can last between 2 to 4weeks

[turtlehead]

What can cause it? I recently changed the filter media is that it?

[Simon]

yes, most likely the cause of the bloom. If you still have the old filter running, place a old filter media in the new filter

[turtlehead]

I left only less than half the media and threw away the old... I thought that was enough.

[janazr]

If could be ineffective media substrat/rings, old perhaps.
You can speed up the bacteria processing by adding a
Liquid Bacteria into your tank.

[vinz]

I left only less than half the media and threw away the old... I thought that was enough.

It should be, but did you transfer over immediately, and started the filter or left it standing or let it dry up. If you washed the media under tap, chlorine could have killed the bacteria. Or the media could simply be too old and clogged.

[turtlehead]

the media left inside the filter I did not wash, I simply took apart the filter took out more that half the floss and replaced it.