I have a 55 with no sump at this point and a hob filter and a korillia 3 powerhead how muc more flow do I need? I heard 3 to 5 times your gallon but that just makes no sense to me that seems Wayyy low my k3 pushed 850 gph what more do I need
Get one more K3 in there and you will be in good shape, as you tank fills in or if you have a ton of rock you need another plan and it also depends on what your keeping in your tank soft corals and fish need less flow than say SPS but the overall health of your tank will be better with good flow throughout.
When I had my 50B I started with a K2+K3. I went snorkeling on a reef for my first time and immediately went home and upgraded to three K3s. Flow is one of the most important and underrated factors in a successful reef tank. Not only is it critical for coral growth, but its going to keep your sand bed clean and improve you skimmer function by keeping organics suspended in the water column.