Bad idea in my opinion especially with a black since there so slender...aros are pretty fragile against tankmates until around 12-18". They fold in half for a very easy meal (ur aro in half 3" is an easy snack for a 7" bass). Id let him pack on some size until u add him to general pop. Aros and bass are fairly good combos but they like to pick at eachother in my experience. The aro should be larger than the bass before u add them together.
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