No skimmer needed, imo.
Most people who go from large systems to nano's cannot imagine a tank without a skimmer but it's common.
Have a good cleanup crew, some nutrient sucking softies & weekly water changes and you can live without.
I have 5 fish in mine, softies like xenia & kenya tree that export nutrients and grow like crazy and 10 hermits and about 20-25 snails (mix of nerite, nassarius, cernith, margarita - only 1).
Weekly 5 gallon water changes.