wounds on my Ryukin

Question
I have had to remove my common pleco from my 15 litre tank as he has ben attacking my Ryukin.  He has been left with some wounds.  I have put Methylene Blue in the water but I am worrying that I have done the wrong thing.  Can you put my mind at rest. Also, I thought that plecos could live happily with any fish.  I'm wondering why he was so aggressive when food entered the tank?  I've been giving him algae wafers at night and tried some cucumber.  I don't know the sex of the fish, but I usually refer to them as males.  

Answer
Hi Sharon
I saw your question in our question pool, so sorry for the delay in answering.

Methylene blue is more of a treatment for fungal or parasite infections.  I'm assuming you don't live in the US, is there a product called MelaFix available where you live?  It's an herbal remedy that's great for wound treatments.  Most pet stores here in the US carry it.  

Plecos generally are peaceful, but occasionally you'll find one that likes to suck on the slime coat of fish.  Usually this happens when there's not enough food for the plecos.  Sounds like you were supplementing him good though.  My thoughts, your tank is too small for a pleco, the common ones grow 12+ inches long.  It's actually too small for a goldfish as well.  A goldfish should have a minimum of 56 L for one, and the pleco would need something much much larger then that.  Anyway, goldfish are notorious feeders, and a lot of times the other fish in the tank can't get to the food quick enough.  The goldie may have been eating the algae wafer before the pleco could.  That would explain why the pleco was becoming "food aggressive", he wasn't getting any, so he had to fight for it.  Probably be best to upgrade to a larger tank, and possibly getting rid of the pleco all together as well.

Hope that helps, and good luck!

Christy