Recommended holding tank pump
I'll second what Peggie said about the diaphragm pump. The rubber impeller-type macerator pumps from Jabsco, Shurflow, Sherwood, and others used to be priced between $189.00 and $250.00. Now you can buy them for $99.00. Any idea why? Because they don't seem to last, and demand for them is drying up. When the lesser-quality pump "dies" halfway through a tank pumpout, what do you do then? You're better off biting the bullet to begin with and get a better quality pump from the outset. Or, get a good quality MANUAL bilge pump and use it for pumping out the holding tank - fairly common on sailboats.