Use this option to add more Root Seekers to your system. Since the Reservoirs can be moved easily from from location to location, you don't need one for every Root Seeker.
Example 25 tree application: Purchase 5 Base Systems and 20 Root Seekers. Install 25 Root Seekers and shuffle 5 Reservoirs between them. While you can't finish as quickly, you can save money! With Tree I-V you can do whatever you want.