[karimwassef]

any way to tell if the bacteria in my black fuzz are gram positive or gram negative?

I'm thinking of local antibiotics (yes - severe, I know). I'm tearing the tank down, so I'm willing to take a few more risks than usual (and my usual is pretty risky)...

so, having looked at these bacteria...

Erythromycin (Maracyn) for gram positive cocci bacteria.
Minocyclin (Maracyn 2) a tetracycline antibiotic for a broader spectrum of bacteria.
Bactrim (Maracyn Plus) a sulfa antibiotic plus trimethoprim for gram positive cocci.
Melafix (Tea Tree Oil)
or .... ?

Any idea which would work best with the least side effects?

I'm also curious about the impact of antibiotics given that my tank is very heavily algae-filtration based.

Of course, everything in connected, so killing bacteria could hurt corals, fish, invertebrates, sponges, and even the algae. And most would kill indiscriminately...

But it's rare that I get to experiment and be ok with a full tank wipe in order to learn (talking myself into it...)

I could just go UV or peroxide or ozone... or just localized bleach if I was getting nihilistic... but I think experimenting with antibiotics could generate some useful findings for others?

for all I know, my very rapid coral growth could be due to a bacterial catalyst somewhere in the tank...

open to ideas ...

I could also take a sample in a little container and add different antibiotics to see what happens.