Supply Lines & System LayoutUpdated 2 months ago

Tubing Overview

Blumat systems use two primary tubing sizes to move water efficiently from your source to your plants:

• ½-inch tubing — trunk lines that carry high volumes of water over longer distances
• 8mm tubing — zone lines that directly feed sensors, BluSoak tape, drippers, or capillary mats

Trunk Lines

The trunk line begins at your water source — just downstream of a pressure reducer or reservoir — and runs toward your zones or rows.

• Made from ½-inch polyethylene tubing
• Uses Permalock fittings and valves for secure, reusable connections
• Can also be built using Schedule 40 or 80 PVC with reducer bushings to convert to 8mm tubing

Why trunk lines matter: Every time you reduce to 8mm tubing, you limit flow to about 1 gallon per minute. This is fine for a single zone, but when paired with a higher-capacity pressure reducer, trunk lines let you split total output across multiple 8mm zones.

Flow matching guide:

• ½-Bar Reducer (~0.75 GPM): 1 zone
• Full-Bar Reducer (~1 GPM): 1 zone
• System-Wide Reducer (~7 GPM): up to 7 zones when properly split using a trunk line

Zone Lines (8mm Tubing)

Once water is split off the trunk line, it flows through 8mm tubing to reach sensors and emitters. Two types are available:

• Black Poly Tubing — slightly rigid, great for straight lines or clean layouts
• Super Flex Tubing — soft and kink-resistant, ideal for weaving through containers or beds

Both types are fully compatible with Blumat fittings. Use Super Flex where routing is tight or tricky, and Black Poly when long, clean straight lines are preferred.

Tips for Consistent Flow

• Keep trunk lines straight and elevated when possible
• Use tee fittings and reducers to cleanly split water to each zone
• Reduce at the point of need — not back at the reservoir — to keep high flow where it's needed
• Avoid long single-direction 8mm runs
• Purge air during startup and after any reservoir emptying

Air Purge Valves — Critical for Gravity Systems

When water flow is disrupted — especially in gravity systems — air can become trapped in the tubing. Even a small air bubble in a low-pressure system (1–5 PSI) can stop flow entirely.

Install ball valves or flush valves at the far end of every trunk line or loop. If your reservoir runs dry and air enters the system:

1. Refill the reservoir
2. Open the flush valves to let trapped air escape
3. Once water runs steadily, close the valves and resume normal operation

Gravity System Layout Options

Gravity-fed systems require special design considerations due to their low operating pressure. Two common layouts work well:

A. Looping from the Reservoir (2 Bulkhead Method)

Best for compact container gardens or smaller raised bed systems.

• Install two bulkhead fittings: one for supply, one for return
• Run tubing out of the first bulkhead, through your growing area, and back into the second
• Water flows in both directions around the loop
• If one side clogs, the other still feeds the system
• Two outlets also increases total flow, allowing more sensors on gravity than a single line would support

B. Trunk Line with Multiple U-Loops

Best for larger gardens or grow rooms on gravity.

• Use a ¾-inch bulkhead and connect a ½-inch trunk line to the bottom of the reservoir
• Run the trunk line along the head of each row
• At each row, install a reducing tee to split into 8mm tubing
• From each tee, run Super Flex tubing in a U-shape: out to the end of the row and back to the next tee
• Repeat for each row

This approach keeps all 8mm runs short for better pressure, builds redundancy into each row, and allows expansion even in low-pressure environments. Always install flush valves at the end of each trunk loop.