Don't worry! Is not your fault, is the fishes. They keep moving.
You just need to be very patient with a macro lens. No flash was used and i suggest manual focus. I just have to look for those not to hyper active one's with better water visibility and do my best. They will have some short moments of stillness. I also have many blur shots but with enough shots, you will sure to get some precious. I spend about 5-10 min with each fish including waiting time. Thanks for the appreciation.
as for setting should I use ISO 1000 and above? And how about the Fstop?
Thanks