Ick - The Truth
Ick, short for
is a parasite
found in EVERY aquarium. Let me repeat...Ick is in all
of our tanks all the time. When a fish is infected it
is commonly seen as tiny white dots about the size of sugar
grains. Every hobbyist, whether freshwater or
saltwater, has either heard of, has experienced or will
The Ick parasite is as
common to the hobby as the cold virus is to human beings.
Why don't we walk around with a cold all the time?
When our immune systems are healthy we ward off being
infected. The same goes for fish & Ick. Ick is
present in all oceans but in such low numbers (due to the
vastness of the oceans) the fish can easily ward off
infections. In our aquariums however, the dense
population of fish in an enclosed environment allows Ick to
quickly take hold & spread.
What causes Ick?
Quite simply...stress. Stress lowers a fish's immune
system making them susceptible to infestation.
Let’s look at the Hippo Tang who has a reputation for being
an “Ick Magnet”. Why is this? Because this fish
has a more nervous personality than most & nervous =
can be caused by one or more of the following:
collection, transportation, poor handling & holding systems,
poor water quality, improper diet, bully tank mates, stray
electricity in our water...and the list goes on.
How to remedy Ick?
First let me stress that prevention is the best medicine but
if you see Ick on one or more of your fish you need to
identify the stress & eliminate it immediately. Also
of huge mention is that as of this time I write there are
NO known safe & effective medicines we can use in a reef
aquarium. Be careful of false claims!
There are those who suggest
that freshwater dips will help.
Understand that the Ick
parasite is protected under the fish's slime coat.
It's only when the parasite goes off the fish that any
remedy will work. Freshwater dips IMO only make
matters worse! Imagine the additional stress to the
fish from being netted then dumped into freshwater only to be
placed back into the aquarium ... now with an even lower
Again, find the cause(s) of
stress & remove it. If yours is a case of
transportation stress (you just bought a new fish &
introduction to it's new home stressed it) and only a couple
spots have appeared on the new fish...I would not worry.
As long as any infected fish is eating and you don't see the
Ick spots increasing in numbers, the fish can easily get
over the infection. Think of it like us humans either
having the sniffles or full blown pneumonia. A couple
of spots (you can count them) = sniffles. Peppered
with spots (can't count) = pneumonia! If the fish is
peppered you may want to consider intervention by means of
Hyposalinity. Hyposalinity is where we lower the salt
level in our tanks to a therapeutic level, usually between
1.014 & 1.016 and raise our tank temperature to about 80
degrees. Understand that the Ick parasite cannot
tolerate salt levels below a certain point. Lower than
they can tolerate kills them! Raising the temperature
actually speeds up the life cycle of the parasite making it
come off the fish faster. Ick is doing the most damage
while on the fish.
If you decide that
hyposalinity is needed then you will want to remove at least
10% of your tank water & replace with fresh water. The
next day check the salinity & adjust as needed to get it to
the therapeutic level. Leave the tank in hyposalinity
for 2 weeks. If no spots are seen at that time you can
salinity slowly by
replacing evaporation with saltwater.
hyposalinity can be hard on corals and inverts. Many
corals will close during this time. You may even loose
a coral but usually that's not the case. I've have
personally used hyposalinity many times successfully.
There is no quick fix or exact cure. Again, the best
method & medicine for Ick is prevention = no stress.
For more information see "Self
Fish Stresses = Disease = Death?