Description
Keep your controller's probes out of the tank and in the flow
The Bluelab Sample Tube and Fittings is a vertical probe housing that sits in a pumped loop from your reservoir, holding the pH, conductivity (EC) and temperature probes of a Bluelab Pro Controller Wi-Fi or Guardian Monitor Wi-Fi in a steady stream of nutrient solution. The probes still read the solution directly, but they no longer hang in the tank: close the valves, drain the tube and lift them out for cleaning and calibration. Because the solution is piped to the tube, the reservoir itself can be awkward to reach or further away; only the tube has to sit within 2 m of the controller, the length of the probe cables.
What's Included
- Sample Tube with conductivity, pH and temperature probe ports, inflow and outflow shut-off valves, and a drain valve that doubles as the manual sample tap
- Hose fittings (1" female thread to 1/2" hose tail), two
- Temperature port plug for use when that port is empty
- Mounting clips with Pozidrive screws, two of each
Key Benefits
- Probes in the flow, not the tank – solution passes them continuously for representative readings
- Three probe ports – EC, pH and temperature (temperature for the Pro Controller; a plug seals it for the Guardian)
- Isolate and drain without opening the tank – shut-off valves and a drain valve make probe service quick and clean
- Drain valve doubles as a sample tap – draw solution for a handheld meter check
- Vertical design stops air bubbles and deposits collecting on the probe surfaces
- 1" threaded ports or 1/2" (13 mm) hose fittings for straightforward plumbing
Probes Knocked, Fouled or Hard to Reach
Probes hung in a reservoir get knocked by hoses and pumps, sit in still corners and are a chore to fish out for their 30-day clean and calibration, so the job gets put off. A dirty or drifting probe then feeds the controller a false reading, and an automated system will dose pH and EC the wrong way with complete confidence, which shows up as nutrient lockout and poor nutrient uptake. The Sample Tube keeps the probes protected in moving solution and turns maintenance into closing two valves and opening a drain.
How to Use
- Mount the tube vertically within 2 m of the controller, with room above and below so hoses do not kink; fix the clips about 165 mm apart.
- Plumb a pumped line from the reservoir into the bottom inflow port and return the top outflow port to the tank, using the 1" threads or the hose fittings; thread tape protects the PVC threads.
- Route the drain valve back to the reservoir or to a bucket on 13 mm hose.
- Fit clean, calibrated probes: push each in fully, draw it back about 6 mm so the tip sits mid-flow, then hand-tighten the collar.
- Start up with all valves closed, open the outflow fully and the inflow halfway, switch on the pump and check for leaks.
- Every 30 days switch off the pump, close both ports, open the drain and remove the probes to clean and calibrate.
Technical Specifications
- Compatible with: Bluelab Pro Controller Wi-Fi; Bluelab Guardian Monitor Wi-Fi (standard version)
- Probe ports: conductivity (EC), pH, temperature (temperature used by the Pro Controller)
- Inflow and outflow: 1" male tapered thread
- Hose fittings: 2 x 1" female thread to 1/2" male hose tail
- Drain: valve with 13 mm (1/2") hose connection
- Maximum pressure: 15 psi (about 1 bar) – low-pressure systems only
- Installation: vertical; controller within 2 m (probe cable length)
- Mounting: 2 clips, 2 Pozidrive screws
- Running both a Pro Controller and a Guardian: two tubes, connected in series
- Bluelab part code: SAMTUB
Frequently Asked Questions
Do I need a Sample Tube?
Not if your probes can hang in the reservoir within 2 m of the controller. It earns its place when you want the probes out of the tank, protected and quick to service, or the reservoir is awkward to reach.
Can one tube serve a Pro Controller and a Guardian Monitor?
No. Bluelab specify two tubes, with the outflow of the first connected to the inflow of the second.
Can it run on mains water pressure?
No. It is built for a low-pressure reservoir pump loop and must not exceed 15 psi.
Which probes go in it?
The standard probes of your Pro Controller Wi-Fi or Guardian Monitor Wi-Fi: the pH probe, the conductivity probe and, on the Pro Controller, the temperature probe.
Works Well With
