Melafix is not as good as the manufacturers say but should not pose a problem with other meds.
As for being a natural product made from tree bark, so is turpentine but I would not put it in my tank. Just because something is a natural product does not make it safe. This is not implying anything against melafix, just that perticular belief irks me. I knew a gal who was always putting aloe on her skin and said "anything natural won't hurt you" but I did not see her rubbing her skin with poison oak. After all, it's not only natural, it's also organic.
An independent survey quote
Melafix 5%
It is not the one-step cure for all ulcerated fish, however, it does promote faster healing of ulcers when used concurrently with other proven technics.
In one test conducted on small koi in a hospital tank for 2 weeks on dosages of Melafix the ulcers did indeed recede. Unfortunately, they never quite went away. These ulcers were not swabbed with Potassium Permanganate or Iodine. The only medication used was Melafix. Improvements in the kois’ ulcerated condition was apparent but the ulcers did not totally heal.
On a second test with small koi, prior to starting them on Melafix treatment, I swabbed the ulcers with Betadine then put them in a 4-hour bath of Furazone Green to destroy much of the external bacteria on the koi. After the bath they were placed in the hospital tank and treated for 10 days with Melafix. After 14 days the ulcers were completely healed.
A third test was done on six large ulcerated koi (14 to 18 inches long). These koi were also swabbed with Betadine and put into a Furazone Green bath. My results were mixed. Three koi with less advanced ulcers started to heal. Two koi with more advanced ulcers did not heal but did not get worse. One fish’s ulcer after 10 days of treatment continued to grow. This fish eventually died which prompted me to inject all five remaining fish with Amikacin for 4 consecutive days. The remaining koi healed quite quickly.
In all test cases any parasites were eradicated before testing began and test tanks were heated to 73°.
Melafix is a good product - one that should be used in treating ulcers. Is it a cure-all? No. Will your fish be cured in all cases when used? No. When used in conjunction with other methods such as bath treatments and antibiotic injections will you get quick healing and a higher percentage of saved fish? A definite YES.
