Hanna pH 7.01 Calibration Solution HI7007L | 500 mL (16.9 oz)

Hanna pH 7.01 Calibration Solution for the Neutral Point

Every pH calibration starts at neutral, and HI7007L is the bottle Hanna makes for that first step. It sets the offset, or zero point, of a pH pen, portable meter or controller probe. The value is 7.01 pH at 25°C with an accuracy of ±0.01 pH, traceable to NIST reference materials. Each bottle holds 500 mL, roughly 16.9 fl oz, under an airtight, tamper-proof seal. The buffer itself is a blend of potassium dihydrogen phosphate and disodium hydrogen phosphate. Labels are color-coded by value, with the lot number and expiry date printed beside a pH-versus-temperature chart. That chart matters in a grow space, where solution temperature drifts with the room. Unopened, the solution is rated for 5 years from manufacture. Opened, Hanna puts its useful life at about 4 to 8 weeks with the cap kept on. No dyes are added, so nothing builds up in the electrode's reference cell.

A pH 7 Buffer Solution Sets the Zero Before Every Feed Check

Neutral comes first because it corrects the probe's offset before the slope is set at the acid point. Reverse the sequence and a meter can read true at one end while drifting across the feeding range. Pour a little into a clean cup, let the reading settle, and confirm it on the meter. Many digital pens accept this point with a single press of the calibrate button. Rinse with RO or distilled water before moving on to the acid buffer. Never return used solution to the bottle, because one dirty probe tip spoils the rest. This bottle also works as a quick drift check between full calibrations. If a pen reads more than a tenth off at neutral, recalibrate before mixing the next reservoir. Store the bottle somewhere cool and dark, away from the nutrient shelf. It pairs naturally with a pH 4 standard and an electrode storage solution.

Key Features

• Neutral offset point: Corrects the electrode's zero before slope calibration, which keeps readings honest across the whole feeding range.
• Tight tolerance: Held to ±0.01 pH at the reference temperature, so the calibration starts from a known value.
• Color-coded label: The coded label and printed temperature chart make the right bottle and the right target value obvious at a glance.
• Sealed bottle: An airtight, tamper-proof seal protects the buffer until the first use.
• Dye-free phosphate buffer: A clean phosphate formula leaves no stain or residue in the probe's reference cell.

Technical Specifications