Fracturing slurries are prepared on the fly using a solids pump to feed the solid such as a gel into a liquid stream of normally water for pumping downhole with a large capacity triplex pump. The solids pump is preferably a Posimetric® style which delivers the solid into the fluid pipeline in a manner that keeps fluid from backing into the solids hopper above the solids pump. A separate fluid tank is connected to a fluid pump to pressurize a suction line to a boost pump before reaching the triplex pump and pumping into the subterranean formation. The solids pump can deliver between the fluid and boost pumps in which case the solids go through the triplex pump or alternatively the solids can be delivered into the higher pressure discharge line of the triplex pump.