Good idea but any further up and they vortex ,I could silicone something to the top slats but this would restrict power Im thinking. Right now,one is lower by a little than the other with both pointing up ,the surface is well rough. What I imagine im createing is two circles,rather than one ,other thought and I have done it in the past is both in sync ,or not? Up one end as high as possible. Seem to remember that for some reason I wasnt happy with it.