Keeping the lights off isn't helping. You need to keep everything the same. the light schedule, water changes, temp... all the same if you want to reduce stress. Fish need stability and consistency in everything.
How to treat a bacterial infection: First off, there are many things you can do to prevent a bacterial infection from happening in the first place. Some of these include:
- Maintaining a proper environment (i.e. clean water) for your fish to live in.
- Separating two quarrelling fish before cuts/wounds get too serious.
- Utilizing proper nutrition (i.e. nori, foods high in protein), and soaking fish food with vitamin supplements (examples: Selcon, Zoecon, Vita-chem; or even Omega-3 fish oil - props to Paul B for the fish oil recommendation). These will help boost your fish’s natural immune system.
- Utilizing a fish QT - to prevent parasites and other nasties (including harmful gram negative bacteria) from being introduced into your DT. This will alleviate the possibility of a "secondary" bacterial infection popping up while the fish's immune system is already compromised from battling parasites.
- Running a UV sterilizer may help in certain situations, as that will lower the overall number of harmful bacteria found in the water column.
When to medicate: Sometimes all the vitamins, proper nutrition and clean water are just not enough. Sometimes a fish's natural immune system needs a helping hand (like our own). When to QT and pull the trigger on using antibiotics is not an easy decision; it's a judgment call.
As a general rule, I only pull & treat if: a) The fish looks really bad or b) It is a newly acquired fish showing signs of infection. The latter is an easy call for me as I QT all new fish anyway. Below is a list of antibiotic medications you can use. It is not a comprehensive list by any means, but just some readily available options. Whatever medication you go with, be sure it contains broad spectrum or wide spectrum antibiotics capable of treating both gram-positive and gram-negative bacterial diseases.
- Kanamycin (ex. Seachem Kanaplex)
- Furan-2
- Nitrofuracin Green Powder (Great for treating “red sores” commonly seen on butterflyfish and some angelfish. It is also useful for healing wounds and treating ammonia burn.)
- Erythromycin & Minocycline combination (ex. Maracyn 1 & 2). If you are confident it is just a gram positive infection, then API E.M. Erythromycin is a good choice.
- Maracyn Plus (No actual experience, and I have read not so good reviews.)
- For really bad infections, I advocate combining metronidazole (ex. Seachem MetroPlex), Furan-2 and Kanaplex to achieve a very broad spectrum of treatment. Props to “hedgedrew” for enlightening me of this.
Although it is not optimal to do so, you can combine antibiotics with copper treatment or Chloroquine phosphate. Since I do not use hyposalinity to treat Ich, I have no experience using antibiotics in hypo conditions. I do not recommend mixing
Prazipro with antibiotics, or any other medication for that matter. It is important to remember that every medication you use depletes the water of oxygen. Combining meds just exacerbates this. Therefore, it is
absolutely imperative to provide additional gas exchange when treating.
DO NOT overdose antibiotics; if in doubt, always underdose. Antibiotics can be harsh on and even kill certain fish; although appetite suppression is much more common. Some advocate just applying antibiotic ointment to the affected area(s) topically, but I have zero experience doing that with fish. Antibiotics will kill
some of the nitrifying bacteria in your bio-filter, but rarely wipes them all out to the point where you see an ammonia spike. However, for this reason and the negative impact antibiotics can have on corals/inverts, I strongly discourage their use in a DT.
