Can fish get sick off food?

[yzf450motoxrider]

I have 2 oscars 1 convict 1 dempsy in a 125 i feed them hikary pellets they used to go crazy after the pellets but recently 1 oscar stopped eating 5 days ago. and the other oscar stopped eating 1 day ago and they lay on the bottom of the tank i just transfered them to the 125 from the 55 yesterday anyone know what could be wrong?

 

[NSKIRK559]

I haven't seen fish get sick off of food before but you might try change food or check your water st as well. Just my 2cents!

 

[ScoobyRacing03]

do you only feed them that? I'd suggest giving them some varity.

 

[NorCaliCichlids]

Water change schedule?

 

[paopanlilio]

yep thay can have digestion problems if fed only one sort of food so variety is a must

 

[yzf450motoxrider]

do a fifty percent water change every week water perameters are near perfect

 

[shamrock]

How much do you feed them and how ofter?