Used LifeGard Aquatics Quiet One 3000 water pump which I no longer need after downsizing.  I was pumping water from a conditioning tank into an upper rack tank, so 6' across and 8' of head space.  This model has been superseded by the LifeGard 4000, which is rated for > 1,000 GPH, and sells for $106.  Unless you need something that powerful, this one will do at a fraction of the price. 

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