Aqua Master Tools Replacement pH & EC Probes: H600, W650, C800 & P700

Replacement pH and EC Probes for Aqua Master Meters and Controllers

These are the replacement probes for Aqua Master Tools meters and controllers that use probes on cables: the H600 Pro, H600 Pro Substrate, W650 Pro, C800 Pro and P700 Pro2. Because each probe plugs in separately, you only replace the one that's worn.

The connector decides what fits. pH probes use a round BNC twist-lock connector. EC probes use a pin connector, in a small or large size. Check the table below, or the connectors on your existing probes, before you order.

pH probes are the part that wears out. The reference liquid inside slowly becomes contaminated, and readings get slower and less stable until the probe won't calibrate. Good storage in KCl solution slows this down, but every pH probe has a working life. EC probes last much longer, but limescale, nutrient build-up or a damaged cable can stop them reading properly.

The W650 Pro Inline and C800 Pro Inline use threaded industrial probes, not these. Those are sold separately.

• pH probe, BNC: a long, double-junction pH probe for liquids. The double junction slows contamination of the reference liquid, which gives it a longer working life.
• pH substrate probe, BNC: a glass-tipped spike in a tough plastic body for testing directly in coco, compost and soft, moist soil. Also fits the S300 substrate pen.
• EC probe, small pin: for liquids, with built-in temperature sensing. Also fits the E300 substrate pen.
• EC substrate probe, small pin: a stainless steel spike for testing in growing media. It's very hard to damage.
• EC probe, large pin: for the P700 Pro2 combo meter only. Reads EC, CF, PPM and temperature.
• Six-month warranty on each probe

Fitting a new probe

1. Disconnect the old probe. Twist and pull for BNC, pull straight out for pin connectors.
2. Connect the new probe.
3. For pH probes, soak the tip in tap water for at least 12 hours. White salt crystals on the tip are normal.
4. Calibrate the meter before use.
5. Store pH probes with a few drops of KCl storage solution in the protective cap.

Order online, or use free Click & Collect from your local GroWell shop. If you're not sure which probe you need, call or message the team with your meter's model name and we'll confirm it.