Mixing Meth Blue and Kanacyn

[billsreef]

In general methylene blue can be mixed with antibiotics if needed.

[TerryB]

My question is why would you want to mix them? Methylene blue has little value as a medication for SW fish anyway. What are you treating for and what are the symptoms?
Terry B

[TerryB]

Thanks for the detailed answer, it makes helping you much easier for me. Methylene blue reportedly increases the ability of hemoglobin to carry oxygen. However, if your seahorses appear to be having difficulty breathing I doubt the problem is a lack of oxygen in the blood. When fish are ailing they often begin to loose the ability to osmoregulate, especially when parasitic or bacterial pathogens have compromised the mucus/skin/scale barrier. MB will not reduce osmotic pressure, but hyposalinity will. This will accomplish making osmoregulation less costly energy-wise and the reduced salinity will subsequently increase the oxygen holding capacity of the water.
Is it possible that the fish are not infected at all? Could the coloration change be a natural result of maturing or symptomatic of a dietary deficency? I do not claim to be an expert on seahorses, but I question the idea of diatoms or cynobacteria growing on animal flesh. How long have the fish been symptomatic? How long have you had the animals? Did you quarantine? How long have you suspected Amyloodinium (correct updated spelling)? If the seahorses had Amyloodinium they would be dead in a matter of days from seeing a dusting on them. Amyloodinium is a parasite unto itself so it is not actually caused by any related dinoflagelettes in your aquarium.
Methylene blue will kill your biofilter, Kanamycin may not. Copper is the only readily available treatment for Amyloodinium, others are worthless. As long as the animals are eating and behaving normally I suggest that you get a better handle on a diagnosis before continuing treatment. Most treatments are stressful and therefore counterproductive when using the wrong one. At this point I am guessing that the best course of action is a large water change with well aerated and aged water. Then you may want to consider hyposalinity therapy and an antibiotic. I would suggest Maracyn-Two (minocycline) or nitrofurazone (nitrofurazone is an antibiotic, but it does have some limited anti-parasitic action). Have you been soaking the foods with a little Kyolic brand liquid garlic extract?
Terry B