Marine Velvet

This disease is nasty, devastating if it happens, and it was the root cause of wiping out my entire 75 gallon tank (aside from a few fish that did not get sick, which I instantly quarantined). It cannot be seen, nor is it possible to know if it has been introduced into your aquarium; thus deeming it an invisible killer. The bacteria of this disease can live in almost any type of water condition, making it harder to cure. It can wipe out an entire aquarium in 24 hours (which is what happened to me), and it attacks the fish internally via the gills. If fish gets sick from this disease, then the fish will experience heavy breathing, lethargy or hiding, and sometimes will bleed from the gills. It is an internal disease so you may not even notice until it is too late.


  • Quaratine fish and use copper medication
    • Aside from acting quickly and beginning treatment, there is no sound cure. This disease is very uncommon, but it does appear in unlikely scenarios (mine was introduced from a coral frag).
  • A bubble wand or spray valve may also help with oxidizing the water.
    • If you take this route then be sure the water of the quarantine tank is only filled at about 75% capacity, or else it will spray salt all over your room.