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I'm not familiar with your current pumps, but I can say the Gyres are pretty amazing. I have an older 150, and it can move the sand around at the far end of a 7' tank without even trying. They do take a bit more maintenance though - I have to take it apart every few weeks for cleaning or it will totally stop working.
You will need to shut the pumps off and let the tank sit for at least 5-10 minutes with the sensor in position most accurate reading. If you try with the pumps running the light gets refracted off the surface turbulence and causes the numbers to bounce around and virtually impossible to get a good reading.
Is this for the bird's nest, or for multiple corals? If for the bird's nest, typically these are placed near the top of the rock work where the light is stronger and should have medium to high flow across it. You can tell if it's getting too much flow by watching the polyps. If they are not extending on the side facing the pump, then it's likely too strong.
For other corals it all depends on what they are, your lighting, and water flow management (wave makers, powerheads etc.) in the tank.
Depending on where you got them from, see if you can get one with lower output like the IceCap units. Another option is to tinker with the output on the Tunze pumps. See if you can adjust them to push more water across the tank.
On my 75 I have a pair of Jebao PP4's 3" down on opposite sides of the tank and are linked in alternating pulse mode. I have power set to 25% and the pulse length set to switch between pumps every 25 seconds. This creates a strong surge flow just under the surface from left to right. When the pumps switch it creates an upper level turbulent wave than rolls across the top portion of the tank in the opposite direction. The flow in the lower portion of the tank is in reverse of the top, but is much more gentle in the change of direction I'm not blasting the corals in the sand bed. I also have twin returns on the ends of the tank and are aimed up to the surface towards the center brace. With them aimed this way it breaks the surface up for plenty of gas exchange, and creates a front to back rolling flow pattern as well. This flow pattern works well in my tank as it is an LPS dominant system with only a few sps corals in it. So it may be different in your tank, but with some tinkering you should be able to get it dialed in to make the corals happy.
You could try putting them vertical instead of horizontal. I have the same issue in one of my frag tanks that is < 12" deep.. I'm using icecap gyre but same principle.. I do have a tunze (don't remember the size/model) pushing diagonal to the gyre from the opposite side of the tank.. I put the gyre pretty close to the water surface.. I have some pretty large ripples/waves on the surface when it spins up. I think my max is 50%.