In the wild, clowns rarely stray more than one metre from their anenome, (or substitute).
(One of the few adjustments they made to finding Nemo which for the most part was quite accurate)
That's why they do so well in aquariums, in contrast to tangs who can swim great distances.
Mine pair have not ventured more than a foot in 24 months now, even if food is on the other side of the DT, they will wait till it comes closer.