It takes about 8 to 10 minutes to deep fry fish in a deep fryer.
When deep frying fish bring the deep fryer oil up to the hot enough temperature and then submerge the fish into the oil for around 8 to 10 minutes.
Usually 8 minutes is enough to fully cook the deep fried fish but if you like your fish cooked a bit more then 10 minutes should do it.
For me deep frying the fish in the deep fryer for 8 minutes is good enough.
Just set a timer for 8 to 10 minutes and then after that time is up the deep fried fish will be done and ready to eat after it cools off.
After deep frying the fish you may want to allow the fish to drain off the oil in the deep fryer by hanging the deep fryer basket above the oil.
That will also allow the deep fried fish to cool off enough to eat as well.
You can also deep fry frozen fish as well but it's best to thaw it out first so that the fish cooks much more evenly.