my oscar is losing its scales i dont know why. i am thinking that a jack dempsey i have is attacking all the fish in my tank.what should i do.the guy at the store i got my oscars from said that it would be a good tank mate but read diffrent. help me out.should i put jack into oyher tank

I would place the Oscar in a hospital tank if possible. Superficial wounds usually heal well in Oscar, but opportunistic infections could complicate your fish healing process.

Sometimes the combination of Jack Dempsey and Oscar don't work out well, but if your tank is big enough, you take your trouble makers out, rearrange the aquascaping, put them back in and this might solve it for good.

What tank size and tankmates do you have your Oscar in?

What are your water parameters?

Pepe
Santo Domingo

unless you have seen by yourself that JD is attacking
your oscar, then you have to separate them. but if not,
then you have to verify your water parameter as pepe had
asked. sometimes, those symptom indicates problem in the
tank

55 gal but i have seen jack attack my oscars before.i have a good size oscar and the jack doesnt mess with him at all.but my other 3 he harrases i only have 55 gal for little while i wil be getting a 150 in afew mnths

then i would agree with pepe, put your oscar at
a hospital tank to avoid further damage.

i found thee culprit this evening.it was my big oscar attacking him.i have two tigers and the bigger one was the culprit.i was in my room and went outside and took a look at him and he looked worse than earlier.he had bite marks this time and wasn't even too much life in him.but i had another tank so i put him in.hope all goes well tonight,crap i'm bummed.i had him for 2 mnths.the bigger 1 i had for 1 week and a half my wife bought him for me as a gift and he's 4 times bigger.

nice to know that you were able to save it on time.
i am hopeful it will recover accordingly. just watch
on water parameter. oscar heal in no time with pristine
water.

i woke up everyfew hrs last night and at 6 this morning he passed.i am very dissapointed.i am going to keep an eye on that tiger osacar.the funny thing is he doesnt attach the 2 other albino tiger i have only my black one he attached.