Iridescent shark with possible tail rot?

Question
Hello,

I used to care for many fish, then got out of it and 3 years ago we were given 2 iridescent sharks in a larger tank.  We recently upgraded the size of the tank but they still only swim in half of it, which I'm not overly worried about.  They seem to dominate the same space that was their old tank.

Recently I decided to add a handful of albino corydoras to help with clean up and add a little more to the bottom of the tank since the sharks prefer the mid to top.  But after a couple days the larger shark's top portion of tail started disappearing and now it seems that it stopped rotting away but now has pink lumps on the end where it 'rotted'.  The other shark seems fine and they all get along.  I have also noticed that the sharks seem to not be eating as well as they once did.

I have had people tell me many different things to treat and now I am more confused that anything.

Please help!
Andrea

Answer
Hi Andrea,

He has Fin Rot.

When a Corydorra gets fin rot, it's not always visible.  You don't always see the coloration of the tail getting filmy, and when my own cory from the petstore had it, he had lost his whole fin before I discovered it.  Fortunately, it's highly curable.

I suspect the shark caught this from the new cory cats, so they all must be treated.

I suggest going to Wal Mart and buying Ich Away.  Though made for Ich, it contains Malachite Green, which is very, very good against fin rot.  Treat the tank with HALF the dose recommended, as Irridescent Sharks are considered to be fine scaled fish and they can't handle a full dose as comfortably as the corys.

Leave it in the tank and just filter it out as you do water changes, beginning in 3 days.

Please do 25% change of water in 3 days.  Please do an additional 10% change every other day for a week after that.  We want to get rid of the treatment, but still get the water up to par without shocking fish.

Also, another note, when you put the medication in, do not leave the filter pads in the filter.  It will filter out the meds. :)  You should remove them so the meds can work.

Additionally - make sure the heat is up to 80F while being treated.  Fin Rot is SO easy to cure, but it has to be with the correct medication.  Although Ich Away is made for parasites, Malachite Green, its prime ingredient, is also anti-bacterial, and anti-fungal.  It will be the best thing for you, other than salt-baths, which I don't recommend for irridescent sharks.

If you need anything else, please feel free to ask.

Happy fish-keeping!

Renee