Pink lumps/growths on fins

Question
Hi,

I have a large indoor tank, with a variety of coldwater fish: goldfish, koi, ghost koi etc.
All appear happy in the environment.
It is well filtered, and I do a 50% water change once a fortnight, and a 75% change with a gravel cleaner approx every 6 weeks.
New water is always treated with Tapsafe, and Interpet No. 8 Fungus & Finrot, so i wouldn't think water quality is an issue.
Anyway, to the question: One of the ghost koi mirror carp, has a pink lump on each of the pectoral fins. There were none when we bought the fish.
Apart from these, this fish is perfectly happy.
It doesn't notice that is has them, no rolling against the bottom, or rubbing against anything, though they seem to be getting gradually larger.
All the other fish are fine.

Can you please help?!

Many thanks,

Karen


Answer
Hi Karen:  Are the lumps symmetrical???  I have to confess but Koi are one of the few fish that I have never taken care of... I would say that if the lumps are symmetrical then I would not worry too much about them.  They may be part of his genetic makeup.  On the other hand... I can not say that I have encountered this before.  What I would do... is this:  I would try to take a really good picture of have someone come out and look at the fish.  There are Mobil vets who do this kind of house-call... and they would be a much better judge of what is going on then I would.  You can also try another expert here... I look up to Chris Robbins and Karen Fields because they both have a wide range of expertise.  I am happy to do some research for you if you'd like me to.  dave