i changed the water the other day when i added the dimpsie the tank is 40 to 50 gallons there are 3 other Oscars and a dempsie all are small the person at the pet store said that they would be OK in that tank until they got bigger none of the fish are bigger than an inch and a half but will change tank in the morning
first thing first: you have an issue on tank size. 50 gallons is way to
small for 3 oscars plus tank mates; you are over stock.
should i add some of the ick stuff or no my goldfish had it and i cleared it right up
since you do not have data on water parameters, you can try medication, no harm in trying to treat the ick.
lfs usually tell their customer that every thing is okey to encourage people to buy more stuff: fishes, meds, etc.