Just to clear up some points on the meds Maracyn 2 is Minocycline a synthetic form of Tetracycline which is a broad spectrum antibiotic for gram negative bacteria, it is at it's most effective in low Ph soft water such as blackwater type set-up but looses it's effectiveness as the Gh and Ph rise. Maracyn is erythromycin which is a gram positive antibiotic and is generally used for some specific instances such as eye infections where Streptococcus sp. is the primary culprit. It is also very hard on BB and is best used in a hospital tank.
Never use Malachite Green in combination with either Tetracycline or Erythromycin however a very effective treatment for Oodinium is API General cure which can be combined safly with 3X sulfa to kill the protozoan and provide excelent coverage against secondary bacterial infections. While I have no doubt after reading what was discribed above that I did get the initional diagnosis wrong both can persent similar symptoms. With out clinical pathology available we do what we can from pics and discriptions. I did want to explain to you how to correctly use the meds. Medacations are often used incorrectly and the results can be much less than desirable especially when attempting to combine medacations and water chemestries. You should also wait 30 mins after using any water conditioner before adding meds to the tank. Use the full doasage of both API 3X sulfa and General Cure in combination and follow the schedual on the package. GL.