Dude what are you doing?
Parasites live in all tanks. Its bad conditions that bring them out and cause outbreaks... For instance cancer is in all our bodies and has the potential to outbreak killing us. You didn't have a heater or correct salinity. That cause an outbreak.
Did you even cycle the tank? It sounds like you put your fish in the middle of a cycle and the amonia spikes and nitrite spikes killed them
Why does everyone always jump to bacteria and diseaseas..... they live in the water no matter what. Its how you control them is key.
You need to get a water test and most likely re cycle your tank. You should also purchase a book to know how to properly set up an aquarium because if you dont know you need a heater you are very wrong. Do you even have a skimmer?
What size tank?
What are the water test results?
People you need to identify the problem not the outbreak, who cares if ich or other things killed the fish they where brought upon by other things.
AND DONT MEDICATE YOUR TANKS. Medication kills fish whether you believe it or not. Proper care of an aquarium and knowing what your doing can be the best thing you can ever do for a sick fish. A fish doesn't get sick in a clean cycled well cared for tank.
I'm not getting into the human/cancer debate...but this is the best advice on here. Understanding how to set-up a SW tank, it's rhythms and chemistry is far more important than treating diseases. In a properly set-up tank, with properly QT'd fish, you would likely never have to treat disease.
The OP, from his opening post, clearly has no idea how to properly set up a marine tank...I mean no heater??? Salinity a "little high"? Considering most LFS keep their salt levels very low (1.015-1.018) to combat cost and parasites, being dumped into a much higher salt without acclimation over a week could easily cause an outbreak of disease or death. "Almost no nitrate, ammonia or nitrite"? Sounds like the tank may not have been cycled.
Buying a book on marine aquariums is the best advice here.
Also, Green Morays rule


