betta fin problems

Question
I have a 30 gallon tank that contains  1 betta, 6 priscella tetras, 5 neon tetras, 1 spotted cory, 4 albino corys, 4 kuhli (cinammon) loaches, 1 small pleco, 1 chinese algea eater, 1 large apple snail, 1 african dwarf frog. and somewhere between 2 and 6 ghost shrimp.

I had a serpae tetra in the tank for a couple of days with the betta but removed it when it started nipping the bettas fins.  I noticed today that almost all of the bettas top and tail(?) fins are now missing and whats left looks like a spiders web of a sorts.  According to my research the tank mates should be compatible witht he Betta.  Is there any disease that could be causing this or is my research given me false info?  please help.

Answer
Hi Jerry,
 The fact that certain fish are "typically" compatible doesn't mean that every individual reads those books, i.e., a particular tetra, or the pleco could easily be doing the damage.  

  Are you feeding the pleco?  All too often people think that the pleco can just survive on left overs.  This is not the case. You need to provide him with food such as sinking algae wafers. If you do not, he could easily take to attacking the other fish in the tank.  

-- Ron
  rcoleman@cichlidresearch.com
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