Is it okay to put goldfish in a tank without a filter but 75

17.5.3. Stocking Goldfish

How to set up a temperate tank - that looks tropical! - Practical Fishkeeping

Is it bad to stunt a goldfish's growth by keeping them in a small tank? - Quora

Goldfish and a sand substrate/s do not mix. Plus, the answer/s from hobbyist to my question.

17.5.3. Stocking Goldfish

Sunfish Care - Keeping Pumpkinseeds, Bluegills and Their Relatives

I have an aquarium with 4 goldfishes but with only an oxygen pump and no cleaning filter. Will there be any problem? - Quora

Can I raise guppies in a tank with no filter or air pump? - Quora

Tank is Cloudy after filter change, Cloudy Aquarium Water Forum

GOLDFISH - ORANDA TRICOLOR Carassius auratus - Aquatics Unlimited