Marine Ich:

This has to be the most common disease found in marine life, especially those kept in aquariums. Luckily, it is also one of the easiest to catch and easiest to cure as long as you act in a timely manner. Marine ich is very similar to ich found in freshwater species, it’s just manifested by a different type of organism. If a fish has this disease, then you will see white spots all over the scales of the fish, along with the possibly heavy breathing and/or “flashing” (the fish moving quickly and brushing against an object). It can also lead to other infections since their immune system is compromised.  This disease is also highly contagious and can spread to nearly every fish in your aquarium if you don’t treat it. Fish are more prone to getting sick from this if they are stressed or have any type of prior infection/wound.


  • Quarantine fish and use copper medication
    • Be sure to read the copper medication bottles carefully. Copper in high concentrations are dangerous to the fish’s gills, so always go by what the recommended usage is per gallon of water, or PPM.
  • Increase/decrease salinity levels
    • Decreasing is called “hypo-salinity” and is the best natural method to kill off bacteria. This must be monitored, as marine fish cannot live in a low salinity threshold for long. But the idea of this is that the bacteria can’t either, and it will die off before harm comes to your fish.
  • Slightly increase water temperature about 2-4 degrees
    • This helps because certain bacteria can only live at a specific spectrum of temperature. If you increase it outside of the bacteria’s norm, then the bacteria will slowly die off. (Fun / disturbing fact: this is happening to the bacteria in the oceans, but not to the harmful bacteria. The increase in global temperature has affected the temperature of the ocean in unison. This is causing the beneficial bacteria to die off, which in turn is also killing the micro-organisms and smaller fish that thrive off of it).