Re: I need help ASAP Pogo- lack of o2 would not cause the symptoms that the OP is describing. Velvet is a very difficult parasite to detect in many marine fish. I can almost guarantee that this is not a water quality or oxygenation issue, the fish scratching is usually a sure sign of a parasite.
Oxygenation and water changes will not help these fish. If the issue were environmental the fish would exhibit similar symptoms at the same time, perhaps with less active fish showing symptoms at a later time, this is not the case here.
If the OP wants to try to save his fish, I would recommend treating it as velvet, little to nothing will be lost if you do and it isnt velvet, your fish will die if it is velvet and you dont treat for it soon. |