Algae - good or bad

[Pussycatdoll]

I am setting up my first marine tank. It is a 325 litre tank that has now been running for 2 weeks - the live rock and sand was moved from another marine tank so is pre-established. We have a growth of very nice looking deep red algae on some of the rocks and wanted know if this is good or bad algae.

The tank has 2 MH lights, a protein skimmer, several power heads and two filters. The conditions in the tank were measured yesterday and are almost perfect, no nitrate, nitrite or ammonium.

We would like to know if we need to somehow get rid of this algae.

Thanking you in advance.

[Pussycatdoll]

Looking at the 'New to the Hobby' forum just now I found a link to a site for identifying algae and I think I have cyanobacteria, which is not good? Now I know what it is I can try to get rid of it. I tried to post a photo but it was too big.

[RyanBrucks]

is it slimey, or encrusted?

if its slimey, its most likely cyano bacteria, and a very common occurence when cycling a new tank. even if the sandbed/rock is taken from an existing tank. moving the sand is going to stir up the bacteria and detritus and cause a mini-cycle no matter how careful you are. this is because some of the bacteria used to be buried from direct oxygen contact (nitrate reducing bacteria), and now some of this is dieing because its not in the exact same 'microclimate' as it was. It will clear up if you are diligent about keeping the water/tank clean and by the sounds of it you are.

if its more of an encrusted algae, it could be coraline which is a good thing.

[RyanBrucks]

some tips:

cyano thrives off excess nutrients. this could be a buildup of detritus from overfeeding, or from using tap water instead of RO water, or many other possible reasons.

cyano thrives on a lack of water flow. somewhat related to detritus, because low-flow spots accumulate detritus at a much faster rate.

I'm sure there's more stuff, so other should hopefully chime in too.


Cheers,
Ryan