flow Rate Calculator

Anyone know where I can find the formula for flow rates needed in a reef tank?

I missed the talk at the reef fest on flow, but did get to speak with Jake about the importance of flow. I do however, disagree on a certain front when it comes to flow.

We were talking about my tank in particular and he told me that I need 4x vortech MP40w. I currently have 2x seaswirls with reeflo barracuda return, and 1x vortech MP40w. He told me that I didn't have enough flow to supply the corals with what they needed to grow properly. I don't know if you can make that judgement without seeing it in person and getting a feel for the tank dimensions, rockwork, water movement, placement, ect.

We were talking about velocity of water being the most important, and long ignored, part of flow. He seems to be a big advocate for vortech pumps, but I have owned a Koralia Mag 8, and while the flow is barely over that of the vortech, the velocity is MUCH higher. The vortech makes a VERY broad stream that carries for about 3-4 feet in my tank. The koralia makes a narrower more powerful stream that carries strongly for over 5' (which was the max diagonal dimension of my tank). The reason I went from the koralia to the vortech was because the koralia was too much velocity and blowing sand everywhere. The vortech was controllable, so I can turn it down if needed. Turns out that I leave it full power since the flow is much more broad and it doesn't blow around sand.

As far as flow rates, you want to follow the recommendations that Adam made, but that is hard to do with the limited information available concerning those measurements. You want as much flow as you can get in your tank, without blowing sand and corals around. You dont want dead spots, but depending on the type of coral you intend to keep you may want lower flow areas for really fleshy LPS corals.