General facts about filtration: The ideal force of a filter would be 10 times the tank volume or more, I myself have filtration worth about 8 times. But fancy goldfish generally don't like being blown around by the filter, and if it's too hard, they simply sit on the bottom to avoid it at all

Some of my babies did at some point, so I turned one of my filters down a bit and aimed them differently so that they'll stir the surface and create currents, but not so strong as they'd force my children to hide

You can see yourself what fits your goldfish more

I have one that deliberately swims in front of the filter outtake and the air stone all the time and she seems to love being blown around by it xD Maybe it tickles her little fins
