Hey, @caab, If you are up for an experiment, next time don't do "basil masacre", instead you can simply rip off the leaves from the stems and keep the plant in the system, soon you will see the new leaves will start growing. Well, at least it is how I grow basil. My plant is about a half a year old and I have harvested it several times already. To be fair though, my basil is in the soil pot, maybe with aquaponics is a bit different. Please share your experience if you try.
Mine is also about 6 months old, I really wanted to reduce my plant height to help out a few of my shorter plants hence the massacre. I'm still seeing good regrowth off of what I did so I think I'm ok. I'd like to get in the habit of using basil more frequently so I'm just taking a few leaves as needed.