help BGK & BP problems!

[oogie]

i have 3 small BP and a 4" BGK in a 20g Qtank, the BPs have hid sence i got them afew weeks ago but they seem to have some darker spots on them but i cant quite tell if its just color or a disease(when i got them they were all bright orange)

and when i got up today the BGK seems to have his two front fins niped a bit and they seem to have some whiteish spots on the ripped parts but not on the rest of his body, and i can see a string/worm? or something comeing out of his left gill its about 1 1/2" but i think it may be a peice of filter floss from one of the filters, iam sorry i cant get a pic plus they all usually hide, also iam sorry my explaneing is so vage but i cant see that well(or spell )

 

[oogie]

ok the worm thing in the BGK gill was gon for a wile but now its back and thicker and longer its comming out of the vary bottom(like ware his chin is)and he seems to trying to disloge it and seems stressed HELP please

 

[Pink-Floyd]

Its not a worm it is poop, their anus is on their chin. 1 bgk needs atleast 55 gallons of water. you cannot keep more than one "electrical fish" together they use mild shocks to know where they are(sonar & ecolocation). BGK's will kill anything in a tank with the electrical sense. Have you witnessed the Bp hurting the knifes? It could be the Ghosts fighting at night. So you need to upgrade your tank soon. I would separate the agressor from the prey. Meanwhile add more "landmarks" to the tank to establish territories and spread out argression.