The Balance score is based on comparing the relative abundance of the major microbial families in your sample with those in the typical saltwater aquarium. This score describes whether your sample has a typical community (higher scores) or an unusual community (lower scores).
A high score indicates that the major families of Bacteria present in typical saltwater tanks are present at similar levels in your tank. A low score indicates that one or more of these families is present at very different levels than in the typical tank.
Taken by itself, a low score should not necessarily be interpreted as a reason for alarm. But it provides a conclusive answer to the question, “Is the microbial community in my tank normal or abnormal?” If there are unexplained problems in the aquarium ecosystem, a low score suggests that disruptions in the aquarium microbiome could be playing a role.