You can have more turnover, you just want to spread it out using spraybars. I have about 6x turnover, and I think that they could handle more, spread out properly. Also, I have my LR built up vertically into a structure, with only a couple pieces resting on the substrate. The idea behind it was actually just to utilize the height and give the SH hitching posts higher in the aquarium, and to maximize open sandbed space, but it does seem to have the added benefit of allowing better flow throughout the entire aquarium. Does that help?