HOLY MOLY !!! How long has this been going on, as it does not reach this stage overnight. There is cloudy eyes, mild fin rot, velvet and heavy infestation in general. the issue here is bacterial and protozoan which are two different treatment regimens. here you have to prioritize and I would choose to deal with the parasite first. Water quality plays an importance and will hold the bacteria at bay while treating for parasites.
I would begin with a freshwater dip for 5 minutes which will offer the fish a little relief BUT,... . This fish is in such distress that making a temp will either give it relief or offer added distress.
The remedy for the eyes are ehthromyacin AKA Maracyn 1. Fin and tail rot would be Maracyn 2 but with the parasite treatment, you can safely use ruby Rally Pro which will address the secondary issues.
For the velvet. . . . velvet spots on the fish that are much finer than the spots seen in Ich making it harder to catch until in cases too late to treat.
Some behaviors associated with a fish with velvet are :
- Scratching body against hard objects
- Fish is lethargic
- Loss of appetite and weight loss
- Rapid, labored breathing
- Fins clamped against the body
- rapid breathing and mucus around the gills
Fish with velvet will typically stay at the surface of the water, or remain in a position where a steady flow of water is present in the aquarium. As the disease progresses outwards from the gills, the cysts then become visible on the fins and body. Although these cysts may appear as tiny white dots the size of a grain of salt, like the first sign of Saltwater Ich or White Spot Disease, what sets Oodinium apart from other types of ich is that at this point the fish have the appearance of being coated with what looks like a whitish or tan to golden colored, velvet-like film, thus the name Velvet Disease.
IF YOURE NOT SEEING WHAT IS DESCRIBED, THEN WE HAVE ICH. Both treat similarly and I would say safe is Copper safe but must be done is a separate quarantine tank.
Is fish eating?
Is it breathing fast or normal?
Melafix is a teak tree oil and will do very little other than aid with fin rot and such.