Measuring water flow in Reef Tank

[mling]

When you read articles about coral’s water flow needs, they use Low, Medium, Strong as reference points. How do you know what “Low” is compared to “Strong” in terms of GHR ? Is there such a thing as too much water flow ?

I have a 45 G with 18” x 36 surface area. I have a 290GHR power head on one side and a 270GPH “sweep” power head on the other 36” side, both are at the same 18” end. I have live rock down the middle of the tank ending in a V shape at the other end, looks like a Y from the top. The water flow at the V end is lower so that’s where my “Low” water flow corals are.

 

[Len]

I understand what you mean. These qualitative descriptions are pretty ambigious.

Here's the idea bout water movement: you want as much of it as possible with as little velocity as possible. In other words, if you can displace 30 gallons a minute but avoid a super strong jet, you're in good shape. Too much is when the water is moving at very high speeds from a "point" source like a powerhead or pump. Tunze now makes these awesome propeller pumps that move a lot of water but at slow speeds.

Your setup sounds fine to me