Which tunzes do you have? If they are controllable you could turn them down. An mp10 is kind of small IMO fir a 90 gallon tank. More importantly what kind of corals are you keeping?
In my 65 gallon sps reef I use two tunze 6095 and 1.5months ago added a tunze nano wave box. Perfect flow and all polyp extension has increased in the tank.
Can't comment on the tunzes/wavebox. However the MP10 is rated for under 60g. I had one in my 65g and it wasn't enough. I recently added an MP40 and I'm very happy with the two.
to be honest I dont know the models. I have had them about 5 years there are 2 large ones and a smaller one. I have sps and lps. The flow seems to much for the lps so I pulled one of the bigger tunzes. Hopefully this helps but I am still interested in the wavebox it seems pretty cool. Is it as easy as set and plug in?