Strongest antibiotic?

[JadeAngel]

Ok, to be quick because I haven't had much time to post...

I posted before about our blue crowntail. He has what seems to be columnaris or another bacterial infection.

It started out with just his dorsal fin looking bleached... then white semi raised spots on his gill plates.

It spread and spread. His dorsal fin looked bleached, his body was half white, and his face was almost all white.

Now it is turning colors a bit. Some pink spots, and the rest of the white is slowly turnin off white, greyish, light yellow... however you would discribe it. Still no texture (slightly raised on the gill plates, the rest has no texture even when you look closely)

Anyway... I've tried EVERYTHING to treat him. Nothing is working. Aquarium salt, a weaker fungal/bacteria medicine, everything suggested to me previously, and last thing I've been using to no effect is erythromycin.

He still has an apetite and eats, and he is almost as active as always... just slightly less active.

He's my husband's fish and he really is attached and refuses the thought of putting him down... so in my last attempt I just ask this.

What is the strongest antibiotic I can get for him? It's either the strongest or he'll die... it's too far spread, and I want to do my absolute best to save him. Also, how long should I wait after filtering and cleaning from this antibiotic, to start a new one?

5 gallon tank, no tank mates. Have been super busy lately, so it's hard to check in, but any advise for a last resort strong antibiotic will help. Thanks

[callistra]

Kanaplex by Seachem. If you can't find it you can try Furan-2 by API or Maracyn Plus (not Maracyn or Maracyn II). I wouldn't use the cap to measure ml though. find something more reliable.

To treat, follow the instructions on the container. It's different for each.

If he is pine coned he needs to be in epsom salts.. no additives (check the ingredients label) 1 tsp per gallon, predissolved.

[JadeAngel]

Thank you Callistra. He's not pineconed, but epsom salt baths was one of the many things I tried. Unfortunately he couldn't be in it for more than 2 minutes without gasping and struggling to breathe and clamping up. I haven't tried either of those antibiotics, so I will search for them.

Again, thanks.