Id say its important but too powerful is not necessary...
Put some large dead mysis shrimp in and watch the bottom if any are able to settle on the bottom then u need more flow it should cycle slow enough for the fish to catch.
Reason being when the fishes **** it will eventually end up in your filters faster then break down instead of breaking down in your tank also this way your fishes won't be exposed to rotting food so hopefully no bacteria infection issues.
My water hardly goes bad i use tap water 24hrs old.
25% water change every 2 3 months
Been doing this for 20 years or so
I have all 15 yr old plus fish
1 emporor angelfish
1 blue ring angelfish
1 majestic angelfish
1 15 year old cleaner wrasse
1 yelow tail Corris wrasse
1 dragon wrasse
No clean up crew because they get eaten
