Meters and testers

pH and EC meters for grow tent feeding

Checking pH and EC before every feed is the single habit that separates a struggling grow from a consistent one. Nutrients lock out fast outside pH 5.8–6.2 in coco or hydro, and an EC that creeps up feed after feed without you noticing is the most common cause of tip burn we see reported in-store. A pen meter takes ten seconds — there's no good reason to skip it.

Bluelab is the trusted end of the range here: the pH Pen (£89.95) and EC Pen (£79.95) are built to last years, the Nutrient Truncheon (£89.95) needs no calibration for quick EC checks, and the Combo Meter (£233.95) or wifi-enabled Guardian Monitor (£314.95) suit anyone running multiple tents who wants one number to trust. For starting out, the Grow Gadgets Hobby pH Pen (£19.95) and Hobby EC Pen (£14.95) do the job without the outlay, and a basic pH Test Kit (£4.95) covers you if a pen ever dies mid-grow.

The habit that keeps a meter accurate

A pH probe that dries out between uses drifts fast and reads wrong when you need it most. Store the probe wet — Growth Technology pH Probe Refill & Storage solution (£5.95) is made exactly for this — and run a pH Probe Cleaner (£5.95) through it every few weeks if you're feeding hard water. Calibrate weekly, not monthly, and always calibrate before you notice a problem rather than after.

Once your numbers are right, the next step is correcting them — see our pH and nutrient control range, and if you're new to coco our coco feeding guide walks through target ranges stage by stage. Free UK delivery over £60, or call 020 3488 0419 if you're deciding between a pen and a full meter.