Envir-o aeration pumps from Blue Diamond Pumps use an electromagnetically operated diaphragm, eliminating sliding parts to limit wear and tear. They incorporate energy-efficient motors and a weatherproof compact alloy casing. A range of CE- and UL-approved models are available in steps from 7.9 to 52.8 gpm. The ETA Series includes a built-in alarm system to detect low pressure in the line via a loud buzzer and LED warning light. 855/450-7867; www.bluediamondpumps.com.