Bet You Haven’t Seen a Tank Breakdown Like This

By Justin Hester

Back in the spring we had a breakout of marine ich in our main tank like I”ve never seen before.  It was killing fish within a day, some of which we we had for 6-8 years with no problem, yet it was only occurring in that one tank.  Our system shares a sump and all the water between 5 tanks, yet only one was getting sick.  It was time to do a little homework on marine ich and see what its life cycle looked like.  What we found was that gravel/live rock was needed for the ich tomonts to encyst in.  Our other tanks were probably not effected because they have no substrate or live rock in them.  In the trophont stage of the marine ich life cycle, the characteristic white dots attach to the fish after hatching at night.  Sadistically after 3-7 days, these Trophonts also jump off the fish at night where they encyst in the gravel or live rock where the fish sleeps.  This viscous cycle is probably responsible for the explosive way that it killed 70% of the fish in our main tank and why there was no effect in our substrate-less tanks.

Marine Ich Life Cycle

It turns out that just after the white spot phase, marine ich will actually burrow and encyst in the gravel.  This is the stage that outlasts most reef keepers’ treatments since they can stay encysted for almost 80 days!  Once they hatch though, the theronts MUST find a host to infect within 24 hours or they will die.  That is the reason we left the tank without fish for that amount of time and why we suggest that everyone sets up a quarantine tank like this.  Its so much easier to QT or do the Tank Transfer Method than it is to catch all your fish, QT them all at once, and leave your tank fallow for 2-3 months!


Moving the Fish and Live Rock

We decided the only way to get rid of it was to get all the fish out of the tank and let it go fallow for 2-3 months to break the ich life cycle.  One saturday in April after a cup or two of coffee, I busted a move and broke the 340 gallon tank down so that I could catch and remove all of the fish.  I then had to put all the live rock back into the tank and stock it with 300 or so snails to eat the algae while the fish were out.  The video shows about 2 hours broken down in time lapse to about 30 seconds.  We are happy to report  that our tank has been free of that kind of outbreak since.