G-Tools Ebb & Flow Tray Valve3/4" External x 3/4" Internal Thread

**This 3/4" threaded valve and bulkhead set is the correct fitting for building a reliable ebb and flow water circuit on G-Tools trays.** It suits growers who want precise control over flood speed, drain rate, or who are plumbing multiple trays into a single recirculating system.

Ebb and flow growing depends entirely on consistent, controllable water movement. This valve gives you a physical tap at the tray itself, so you can slow the fill rate when running a delicate propagation cycle or open it fully for a fast flood during peak vegetative growth. That level of on-the-fly adjustment is not possible with fixed pipework alone.

Installation is straightforward. The bulkhead lead-through pushes into the drain aperture on the base of the tray. The locking nut threads on from the underside and pulls the fitting tight against the tray wall, creating a watertight seal without sealant in most cases. The 3/4" valve then screws directly onto the fitting. The whole process takes a few minutes.

The 25 mm PVC connection on the far end of the bulkhead means you can link directly into standard metric irrigation pipework. This makes it easy to run a shared supply or return manifold across several trays on a G-Tools grow rack. 25 mm push-fit and solvent-weld PVC fittings are widely available, keeping future modifications simple.

If you are running this valve on the return side of the circuit, partial closing it creates a useful back-pressure that slows drainage. This extends the flood period without changing pump timing. On the supply side, use it to balance flow between multiple trays fed from one pump, ensuring each tray fills at the same rate.

Grower’s Note: In ebb and flow systems, drainage speed affects how long roots sit in nutrient solution. A slightly restricted drain valve increases flood duration without altering your timer settings. Start with the valve fully open, then close it incrementally by a quarter turn and observe flood duration over two or three cycles before making further adjustments. Always check the bulkhead nut for tightness after the first few flood cycles, as thermal expansion from warm nutrient solution can slightly loosen fittings.

Priced at £36, with free UK delivery.