The Flo-n-Gro® Riptide Under Current® system was built with serious growers in mind. Built in cooperation with Current Culture H2O using their patented methodology known as Sub Current Culture, this system creates explosive growth and record breaking yields. A powerful mag-drive pump coupled with an efficient, high quality linear air pump creates a highly oxygenated and balanced environment for your plants roots. 3 in piping allows for optimum flow throughout the system. Bulkhead fittings allow for a water tight connection to the plant sites. This system features 13 gallon growing sites, heavy duty 8 inch mesh pots, and sturdy injection molded lids with port hole. The Flo-n-Gro® Riptide Under Current® 4 site expansion kit includes everything you need to expand your existing system by 4 growing sites.