clown fish bump/tumor!!help!

[wafi]

hi, so recently my friend gave me his clown knife fish bc he was leaving for 6 month. I noticed that one of the clown knife has a bump( i think its a tumor) near his head.

I have a picture of it but not sure if you can see it.

The two clown knifes are about 15-17inches long. I also have 3 albino tiger oscars 2 of them are 6-8inches long while 1 is 3-4inches long. I also have a jack dempsy that is 5-6 inches long, A parrot fish that is 3-4inches long and two pelco that are 10inches long.

Do you why he has that bump? should i be worried about it??
Is there a way to get rid of it??

 

[Rbishop]

Curious..what size tank? What are your current parameters on the water and what filtration?

 

[wafi]

i have two fluval205 filters. my tank is about 20-25gallons
waht do u mean by parameters on the water?

 

[texasguy]

Here's what www.aqadvisor.com came up with

Warning: Clown Knife is not recommended for your tank - it may eventually outgrow your tank space, potentially reaching up to 36 inches.
Warning: Jack Dempsey is not recommended for your tank - it may eventually outgrow your tank space, potentially reaching up to 10 inches.
Warning: Parrot Cichlid is not recommended for your tank - it may eventually outgrow your tank space, potentially reaching up to 10 inches.
Note: Common Pleco needs driftwood.
Warning: Common Pleco is not recommended for your tank - it may eventually outgrow your tank space, potentially reaching up to 18 inches.
Warning: Your selected species may eventually require 2208% of your aquarium space. You may need to deal with territorial aggressions later on. Try removing some of (Notopterus Chilata, Rocio octofasciatum, Hoplarchus psittacus, Pterygoplichthys pardalis) or get a larger aquarium tank.

Recommended temperature range: 25 - 28 C. [SIZE=-1][Display in Farenheit][/SIZE]
Recommended pH range: 6 - 7.5.
Recommended hardness range: 1 - 15 dH.

Warning: You NEED to add more aquarium filtration capacity!!!

Your aquarium filtration capacity for above selected species is 20%.
Your tank is too small - it will require massive amount of frequent water changes each week!

Your aquarium stocking level is 678%.[SIZE=-1] [Generate Image][/SIZE]
Your tank is seriously overstocked. Unless this setup is temporary, you should consider a larger tank.

And parameters are ammonia, nitrite, and nitrate levels taken with a liquid test kit.

 

[wafi]

i have a 70gallon tank, going to move them there within a week, the tank glass broke and i needed to fix it.

but the bump was there before i moved it into the smaller tank