Odd, typically aquaponic grown food tastes really good as long as it gets enough nitrates and proepr ferts. What fauna did you use to feed the potato nitrates?Good luck with those. I vowed to never plant sweet potato again. The vines took over....and they tasted horrible after all the trouble.
If you try again water it with removed tank water, may help-others with veggie gardens and tanks do this and swear it improves the plants size/flavor.Oh, lol, No, I grew them outside in the soil. Huge ones too, I had such high expectations, the mother potato tasted so good.