I'm building my first planted tank and while doing some research I noticed nobody uses regular goldfish for their tanks. I know they don't do groups, but they sure make great contrast with the plants. What am I missing?
Regular gold fish... Do you mean the ones they sell as feeders?
I have seen very gorgeous planted tanks with a single fancy goldfish in there before. The fat ones with really nice tail fins.
I'm usually not even a big fan of goldfishes, but that one really stood out
In any case, if you meant all goldfishes in general, then I believe it IS possible to keep them with plants they won't eat.
I believe Java Ferns taste bad and things that normally eat plants tend to ignore java ferns. Maybe you can use those in a goldfish tank.
I keep a single large Ryukin in my 90 gallon. He's up to 8" tip to tip and doesn't affect the plants that much. But then I don't 'do aquascape' and I'm keeping easy stuff, so I wouldn't care much what he does to the plants.
Here's an older picture, he's bigger now:
I will never keep anything BUT goldfish from now on. Great personality (for a fish) friendly, will eat out of your hand, lets the kids mess with him...almost like a real pet.