need to deworm?

Hi here. anyone knows whether it is neccessary to deworm goldfish? i have kept my gfs for about 1-2 years but never do any deworm b4(they are still alive and healthy i guess).

By the way,what does deworm mean?

using medicine bought from lfs to clear the intestinal tract of the fish.

Do it only when they loss appetite or signs of worm appear at the wall of the tank.
Deworm powder is expensive you know, but is good to stand by the powder, just in case

i doubt u need too.. but if u wanna be safe yet i think u cld do it...all the best