> I hate to pee on the parade, but IMO, the use of antibiotics in this
> fashion is not the way to go. You are getting more cyanobacteria than
> you want because there is a problem with either the chemistry or the
> biology of the system.
> If I had to venture a guess, I'd say that your tank is probably short on
> some microbes or very small arthropods that eat cyanobacteria. Your tank
> may have more phosphate than it needs. Adding erythromycin doesn't take
> care of either problem. It will however eventually breed resistant
> cyanobacteria and bacteria.
> Your analysis of the aftermath is essentially correct. The cyanobacteria
> died, their nutrients went into solution, where that bacame bacteria
> food. There was a bloom of bacteria, prehaps accompanied by a spike of
> ammonia, which your plants probably helped with immensely. Eventually
> the system comes back under control.
> If anyone else tries this, you should watch the dissolved oxygen
> concentration, especially at night. Based on my experience with
> antibiotic use in reef aquaria (where there is also a bacterial bloom) if
> the bacterial bloom is sufficiently intense, you may lose some fish to
> anoxia at night. Theoretically, you could crash a tank this way,
> although I doubt that will happen very often in practice.
> The cyanobacteria always comes back in reef systems if something is not
> done to address the underlying problem.
I do not particularly feel that using the antibiotic in my tank is a good idea
either, but I haven't come up with any sound advice on how to remedy the high
phosphate or lack of microbe-eating bacteria situation.
I have a freshwater tank, well planted, and do bi-weekly H2O changes. I've
never seen the PH fluctuate (7.5), but over the past few months, the GH & KH
Do you having any solutions to get rid of the cyanobacteria? I've seen the
phosphate filter pads but haven't tried them yet. Are these effective?
Any comments would be appreciated!