i grabbed 3 silver dollar while i was getting oscar are they good tank mates for him,as ive noticed they are pretty quik.....i hope he doesnt eat them...

As long as they are big enough to not get eaten you will have great tank mates... How big is your tank?

i have got a 160lt tank a bbig enough filter to cope with it that sits completley submerged in the water,i have the 3 silver dollars i have oscar who is about 6inch long and in there own stick on the side of the tank compartments i have 8 fighters males...dont know the nitrite and nitrate levels because only just over the last 4 days set up tank.

OK Hun, you can't add anything to that tank.

It is only 42 gallons and not big enough for your Oscar. You need to look for an upgrade..

As for your filter, what brand/kind is it?

How long has the tank been running with fish in it? Did you cycle?

how big a tank should i go

You need to look for at least a 350 liter tank for the stock you currently have. And then you need to get yourself a good canister filter that will move a minimum of 1200 liters per hour. Check ebay, you can get some great deals!

And when you set up the next tank, cycle it before putting your oscar in it. I killed my oscar baby by putting him in an uncycled tank. Don't want that to happen to you!

having an uncycled tanked could risk your fishes. i hope you can
handle the labor to keep your ishes alive.

i suggest you get a prime and don't clean the filter yet. feed the ishes sparingly
and remove any foods left two minutes after feeding.