Re: cyanobacteria solutions?

     Every aquarium I have ever had (both salt and fresh) with 0 ppm 
     nitrate developed blue-green algae problems.  Cyanobacteria are able 
     to fix atmospheric nitrogen, and can grow in a nitrogen-poor 
     environment.  It is a metabolically expensive process, but they can do 
     it.  I keep a barrel of rain water for the carnivorous plants in my 
     greenhouse, and guess what?  It has blue-green algae growing in it!
     I have been using PMDD for about a year, and my blue-green algae 
     problems have vanished. I don't recall seeing your nitrate level, but 
     I am willing to bet it is 0.  Also, if you have a high phosphate 
     problem the use of PMDD will lower it.  If you don't already add CO2, 
     I recommend that, also.
     Recurring outbreaks of blue-greens indicate something is out of 
     balance, and I guarantee it is easier and better to remedy the cause 
     of the problem, rather than a temporary antibiotic quick-fix.   Good