The typical simplified Aquarius Water Systems Reverse Osmosis Plant consists of:

Pre-filter
Typically of less than 5 micron rating.

Main feed pump
Multi-stage simplex or duplex pumps to generate osmotic pressure.

Membranes and Element housings containing reverse osmosis membranes
membrane housing interconnected with 316 stainless steel and ABS pipe work.

Control panel
Incorporating pressure gauges, flows, alarms, conductivity measurement and meters.