This question is missing some essential information, like how big are the particles and what is their density?  Without that information, I can only turn the problem around.  Assuming that the particles are sand-like with a specific gravity around 2.4 (2.4g/cm), a 889 mm diameter, hydrofoil running at 84 rpm will be able to suspend (off-bottom) particles as large as about 100 microns (0.1 mm) in diameter.  Particles as large as 150 microns (0.15 mm) in diameter will only be kept moving on the bottom of the tank.

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