pH & EC Meters. Hydroponic Testing & Controls

Accurate pH and EC monitoring is essential for healthy hydroponic plants and maximum nutrient uptake. Apex Grow stocks a professional range of pH meters, EC testers, combination meters, and automated dosing controllers from the world's most trusted brands, including Bluelab and Apera. Whether you need a simple waterproof pH pen for daily testing, a Bluetooth-enabled 3-in-1 combo meter, or a fully automated pH and EC dosing system for hands-free nutrient management, our range has you covered. We also stock calibration solutions, probe care kits, and replacement sensors to keep your equipment accurate and reliable. Melbourne-based with fast shipping across Australia.

Combo Meter or Separate pH and EC Meters?

A combo meter measures pH, EC, and temperature from a single probe in one reading, rather than needing two separate pens. For most home and small-scale growers, a combo meter is the simpler, more practical choice: one device to calibrate, store, and carry to the reservoir. Dedicated separate pH and EC meters suit growers who want a backup if one unit fails, or who prefer a compact pH tester pen for quick spot-checks without carrying the larger combo unit. Either approach gives you accurate readings and the real difference is convenience versus redundancy.

Choosing the Right pH Tester for Hydroponics

Not all pH testers are equal. Consumer pH testers from hardware stores or aquarium suppliers often drift quickly, are difficult to calibrate accurately, and do not hold calibration long enough to be reliable in an active grow. A professional-grade pH meter like the Bluelab Combo Meter or Bluelab pH Pen holds calibration longer, is easier to calibrate accurately, and gives you a reading you can trust every time. The cost difference between a cheap pH tester and a Bluelab is small relative to the cost of feeding your plants at the wrong pH for a full grow cycle.

Not sure what pH or EC to target? Our EC guide for Australian growers covers target ranges by growth stage and crop type, and our pH dropping guide explains the most common reasons pH drifts and how to stabilise it. Need a quick fix instead of the full guide? Our Troubleshooting Index covers common pH and EC problems in a fast, dot-point format.

Free shipping runs on three tiers to VIC, NSW, QLD, SA and ACT: $150 or more up to 3kg, $250 or more from 3 to 5kg, and $350 or more from 5 to 12kg. This entire category is genuinely lightweight, from a basic pH pen through to our automated dosing controllers, so weight is almost never the limiting factor here, only your order value. Most orders on this page qualify at the $150 tier.

Troubleshooting pH and EC Readings

Getting inconsistent numbers even after calibrating? Our guide to inconsistent pH meter readings walks through probe care, storage and calibration issues step by step. If your plants are showing deficiency symptoms despite feeding correctly, the cause is often pH-related nutrient lockout rather than the nutrients themselves, our nutrient lockout guide explains how to diagnose and fix it.

Frequently Asked Questions

How often should I calibrate my pH meter?
Before every use is best practice, or at minimum every few days during active grows. pH probes drift over time, and a meter that is even 0.2 off can cause you to feed at the wrong pH without knowing. Use a fresh calibration sachet each time and do not reuse old calibration solution.

What pH should I run my hydroponic system at?
For most hydroponic systems running in coco or mixed media, target 5.8 to 6.2. For recirculating systems like DWC and NFT, 5.5 to 6.0 is typically better. Letting pH drift outside these ranges causes nutrient lockout even when the nutrient concentration in the reservoir is correct.

What EC should I target in my hydroponic reservoir?
Seedlings run 0.8 to 1.2 EC. Vegetative growth typically runs 1.4 to 2.0. Flowering runs 1.8 to 2.4 for most strains. Start low and increase gradually based on plant response rather than chasing the top of the range from the start.

How do I store my pH probe to make it last longer?
Always store your pH probe in storage solution, not plain water and never dry. Dry storage permanently damages the glass membrane. The Bluelab Probe Care Kit includes the storage solution and cleaning sachets needed to maintain probe accuracy between uses.

Do pH and EC meters qualify for free shipping?
Yes, and usually at the lowest tier. Every product in this collection, including the automated dosing controllers, is well under 3kg, so an order of $150 or more ships free to VIC, NSW, QLD, SA and ACT.