black spots in the sand

[Nautilus1]

I have black spots about 2 inches down into the DSB. They are growing between the glass and the DSB. Anyone know what this is?

 

[Mihai]

Likely cyanobacteria. Not to worry. The other posibility is that your DSB is lacking oxigen and you're building nasties but it's unlikely.

M.

 

[Anonymous]

a dsb is supposed to be lacking oxygen-that's how denitrifying bacteria's habitat develops

 

[Mihai]

Well, I think that it gets black is too little oxygen.
M.

 

[JamisonRD]

The de-nitrifying bacteria that thrive in a DSB are anaerobic, and must be to do their job. (Anaerobic literally means without air... so no oxygen deep in the bed is good) As your sand becomes more 'live' and your critters stir it around, it will be less noticable, I believe. From what I understand, this is normal and desirable.

 

[Anonymous]

there are various bacteria that all contribute to the job-aerobic, anoxic, and anaerobic-the whole point of dsb (or plenum) is to allow ALL of these various zones to be created, to provide an environment for all of the various groups-each of which performs a different part of the chain's functions :wink:

the 'black spots' are most likely a sign that things are developing the way they should be :wink:

 

[Nautilus1]

Some bacteria are obligate anerobes and some can thrive in both anaerobic and aerobic conditions. Does anyone know if the dsb contains obligate anaerobes

 

[WRASSER]

what i think they are saying is it is ok :!: