I haven't kept Goldfish in a long while and want to try keeping them again. I had them when I was very young. I was think of atleast 2 Fancies or 3, depending, but most likely 2 fancies is enough. I do have a Cascade 300 (rated for 100 gallons) running on it. I no longer have plants in the tank just wood and rocks, have since moved my tetras to my 55g where they are very happy. I'll upload a picture of the tank in a bit.