Yeah I agree they definitely need supplementing although they have awesome flow, might not be amazingly manufactured but they definitely are great at moving water. My tunzes are just 2x6025 and 1x6015 so non controllable ones. One pump blows along the back just for movement under the gyre where a large dead spot occurs. The other two point diagonally through the tank, meeting with the flow of the gyre when it's in forward mode. Once the gyre goes into reverse mode, and isn't disrupting the flow of the tunzes, the tunzes just blow toward the opposite corner. With this set up and the gyre going in reverse mode every few minutes I seem to have covered all dead spots, so no detritus (and hardly any sand lol) seems to settle in the tank, it just all settles nicely in the sump where it's easy to remove.