Coralife Calcium Reactor 250 Easy-Twist CA+ Reactor Chamber Cover (3” dia.) with pH Probe/Sensor for a pH controller or monitor and a Inlet Fitting Integrated Clear CO2 Bubble Counter and CO2 Check Valve Reactor Intake Media Strainer 3’ Water Supply Input Tubing with Strainer Water Supply Control Valve Removable Self-Priming External Pump Clear Water-Flow Indicator Chamber 3’ CA+ Reactor Output Tubing Compact High-Grade Acrylic Construction CALCIUM MEDIA (such as the Aqua Medic Hydrocarbonate Reactor Media) and CO2 SYSTEM REQUIRED, but NOT INCLUDED. For tanks up to 250 gal.