EBB-FLO® flood benches can be filled and drained about 50 feet from one location. Longer benches need to be filled from two or more locations. The wells, or sumps where plumbing connections are made, are molded into the end trays of the plastic EBB-FLO® liners. For benches up to 50 feet in length, the plumbing can be connected to one end of the bench. If the bench is longer, it will be necessary to run plumbing to both ends, or split the trays on the bench into two or more parts. Splitting the trays on a bench into two halves is the most common way to use longer benches. The fill and drain lines can be run to the center of the bench instead of to both ends, ultimately saving on pipe and fittings.
Most installations with more than one "zone" use the fast fill valve for the connection of the plumbing to the EBB-FLO® flood benches. The fill valve uses a simple venturi principle, has no moving parts, and is very reliable. The fillvalve provides both fill and drain to the bench tray at the one location. As soon as the zone (solenoid) valve is opened, the bench begins filling through the fill valve, and the water is aerated at the same time. As soon as the zone valve is closed, the drain on the fill valve establishes a siphon that rapidly drains the bench.
The drain line drains by gravity to a sump pit (with a high capacity sump pump) if the storage tank is above ground, or directly into the tank if it is located below ground. Tanks located above ground are typically the white polyethylene type available locally at the farm supply store. Below ground tanks can be similar tanks (that are designed for below ground use), or concrete such as a septic tank. Each has its advantages and disadvantages. Above ground tanks are much easier and cheaper to install and maintain, however they do take up valuable space, and if placed in the greenhouse exposed to light, they can have tremendous algae growth. (this can be prevented by painting the tanks black, or not locating them in the greenhouse). Below ground tanks cost more and are more of a problem to install and clean out, etc. However they have no problems with algae growth, and eliminate the need for a sump pump to move the water from the gravity drains from the benches back into the storage tank, and they don't take up any valuable space.