> I am a firm believer of actual antibiotics. YOU WILL KILL US ALL. The US is the last country on earth to get this but use of antibiotics has almost gone away. You can't get these any more in other countries. Here's why: Resistance. Used improperly (and that means not completing the 15 day course of treatment) the few bacteria it didn't kill mutate and develop a resistance to the drug, and worse then have been shown to be able to pass this resistant gene on to other bacteria. Alexander Fleming said in a 1945 interview in Time that this phenomenon is the single biggest drawback to their use. The main problems with antibiotics are 1) they don't do anything in the water. Sero, zip, da nada.The fish have to eat them. 2) You have to test the antibiotics first to see if it kills or rather still kills that species of bacteria. 3) Mycobacteria. This is a killer. Literally. In places like Germany it's really only used by vets any more on on things like $15,000 koi or $20,000 marine angels. The culture the bacteria in a petri dish,test the antibiotic they intend to use. The thye soak food in the correct dose of the antibiotics and feed it to the fish for 20 days. You put antibiotics in the water... none of is gets inside the dish. Will is quite right, if you dose antibiotics in the water and the fish got better, it wasn't the antibiotics. Plus they kill all the nitrifying bacteria. Mycobacteria is really serious: a) It's in all wild water, period. b) It's in all fish, period. But fish have to be really unhealthy to get sick from it, a normally functioning immune system keeps it at bay. c) It's zoonotic. That is, it's one of the very few ad rare pathogens that can infect more than fish. Most diseases are extremely specific, for example the rat lungworm can only lice in the lungs of rats and nowhere else. But mycobacteria can infect fish, people and who knows what else. It kills people. In humans it's known as "swimmer's itch" or "aquarium granuloma" http://en.wikipedia.org/wiki/List_of_cutaneous_conditions#Mycobacterium-related If you get it it's painful and is a bugger to get rid of, it takes 3 months of antibiotics. A couple of people on the net have had it, it's an awful disease. An aquarist in Germany got it, didn't seek treatment and when it got bad he refused to have his arm amputated and died of it. Guess what other disease is caused by a Mycobacterium? Tuberculosis. One of the biggest problem today is antibiotic resistant tuberculosis So, given Mycobacteria are in all water guess what happens? You're strengthen the resistance of Mycobacteria to Antibiotics. If it ever becomes antibiotics resistant, we're screwed big time. People will die. Now, it can't get through the skin. So never never never stick your arm in a tank if you have a cut. Always wash your hands really well after they're in a fishtank. Be aware also that soap is insanely deadly go fish so make sure you get it all off; the tiniest trace under a fingernail can wipe out a tank n under 5 minutes. Ask me how I know. Do not under any conditions use that antibacterial soap, it just strengthens resistance.