Is this just a diatom bloom?

[DonF]

Tank was started about 9 months ago. We had a diatom bloom a few months in which cleared on its own after a few weeks. It had been been clear until just recently. The new bloom seems to have coincided with us starting a dosing regiment to support hard corals, which may be normal? Anyway, no biggie, but a few weeks ago we added “corraline in a bottle” and now we’re seeing this red, rusty color on top of the diatoms.

My question is, is this just regular diatoms or something new growing on top of diatoms? See how it’s also started to creep up the glass? You can see the older brown diatoms mixed in if you zoom in on the picture. I don’t think corraline would start so fast and vast, so as much as I’d like it to be corraline I’m guessing that’s now what we have?

 

[vetteguy53081]

Cyano bacteria
Siphon up and do small water change and verify phosphates befor water change.
Quickest defense is to reduce whites and add ChemiClean which knocks this right down.

 

[DonF]

Cyano bacteria
Siphon up and do small water change and verify phosphates befor water change.
Quickest defense is to reduce whites and add ChemiClean which knocks this right down.

Sorry, I’m a newb. Does reduce whites mean to reduce white light?

 

[S.Pepper]

Sorry, I’m a newb. Does reduce whites mean to reduce white light?

Yes.

 

[Jason Truong]

Looks like cyano. Reduce feeding and lights. It comes and goes sometimes, especially if your tank is newer.

 

[DonF]

Yes.

Thank you!