lump on my fish

Question
I am sorry to bother you but i am worried about my fish i have looked on the internet but have had no luck.
Bellow is as much information that i can think of.

I have a cold water - fresh water tank with 2 goldfish, 2 guppys (although people say guppys are tropical these two are happy crators who luv playing in the spray of the filter, i have been told they adapt to cold water and these two have wonderfully) an algi eater (the type that sucks the glass and rocks ect) and two of another type of cold water fish.

I'm affraid i cannot remeber what the fish type is of the one that has a lump, he (speedy) is around an 1.5", a peachy skin toan colour, is quick and act like miniture salmon (they like to shoot about the tank and can be jumpers)

I notised around twenty minutes ago that a lump has appeard on his left hand side, it looks like streached skin and resembles a spot you may get on your face, it is about a mm in width and is slightly pailer than the fish.

The fish tank was moved recently so they suffered a DRASTIC tank emptying and clean and ofcourse may have become stressed as we had to empty the tank to move it safly without damage. he doesent seem out of charicter however it may only have developed today.
We gave them a new plastic rock with plastic leaves two days ago but cleaned it with boiled water befor putting it into the tank, they are fed every second day and are in a tall tank with water 22.5" deep 18" length and 10.5" width with a strong filter. real plants have been replaced by artificail

I have looked on the net but cannot find an answer to what it is, I hope you can help me to help my fish asap

Thank you for your time
Louise

Answer
Hi Louise,

 It is hard to say. It could be an infection, but it also could be a bite mark from another fish.  Isolating him to give him a chance to heal would be the best move.  

 By the way, guppies are warm water fish and they won't adapt to cold water. They will tolerate it, but they won't adapt to it.

-- Ron
  rcoleman@cichlidresearch.com
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