It depends on what is meant by planted tank, whether a tank where some nice plantings are included, or a truly spectacularly landscaped tank, with very varied and detailed plantings including delicate species in high maintenance fashion.
If the former, a number of large fish are possible. If the latter, most knowledgeable people will only include few and relatively small fish. I only keep the first type of tanks above.
The first tank is 6 foot long, the flagtail Prochilodus is close to 10 inches, and the Hemiodus over 7 inches each.
The second tank is 4 feet long. Silver dollars and planted tanks are possible, but it takes some fish training, creative plant choices (limited depending on the types of SDs), and reasonable expectations from the owner and from the fish. The tiger dollars are ~3.5 jnches, the Colombian tetras about 2 inches.
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