are the powerheads both facing one way? The flow looks rather linear, the yellow stuff stays at the surface and goes from right to left. Perhaps put them at opposite ends of each other so the flow meets in the middle and creates some random patterns. And the flow can be turned up IMO, I have a mixed reed and my flow is stronger than that. I have 2 gyres in a 40 breeder both set at about 55%. If you have an airstone, it will help you more than the yellow stuff.