I found out in one night that minnows may not be suitable in my system. I found seven dead little fish this morning. They didn't even get a chance to float. I can think of many reasons as to why they may have perished. Temperature, stress, differing water quality than the fish store, etc... In the end what ultimately matters is minnows are too fragile for my aquaponic system. I take every fish death as a lesson. I haven't lost a fish in a few days before these new ones. I see that as an improvement from earlier days as well as a reminder on how to improve.