HM Digital pH 4.0 Buffer Solution - 20 x 20 ml Packets - 20 Count

Fresh pH 4.0 Calibration Liquid for Every Meter Check - 20 Packets

A pH meter drifts over time, and a drifting meter gives you wrong readings for your nutrient solution. This pH 4.0 buffer solution gives you a known reference point to calibrate against. Each packet is designed for one-time use, so you are not reusing liquid that has been contaminated by electrode rinsing.

This unit holds 20 packets of 20 ml each. That suits regular indoor growers who calibrate on a routine schedule, as well as hobbyists and small commercial rooms that want ready-measured portions without opening a large bottle.

Key Features & Benefits

• pH 4.0 buffer — gives you the low-end reference point for a two-point calibration.
• 20 individual packets — each calibration starts with fresh solution.
• 20 ml per packet — enough liquid to submerge a meter electrode for calibration.
• Single-use design — helps keep readings accurate by avoiding carry-over contamination.
• Brand-independent use — works with all brands of pH meters and electrodes.

Who Should Use HM Digital pH 4.0 Buffer Solution

Growers running hydroponic systems, indoor cultivation rooms, or any setup where nutrient solution pH matters will find this useful. It also suits aquarium keepers, water treatment users, and laboratory calibration work.

About HM Digital pH 4.0 Buffer Solution

HM Digital makes water-quality meters and calibration supplies. This product is a pH 4.0 buffer solution sold as 20 packets of 20 ml, intended for precise calibration of pH meters.

Frequently Asked Questions

Q: What is a buffer solution?
A: A buffer solution holds a fixed, known pH. You place your meter probe in it and adjust the meter to match that value, which corrects drift.

Q: Will it work with my meter?
A: It works with all brands of pH meters and electrodes. Check your meter manual for its calibration steps.

Q: Can I reuse a packet?
A: No. Each packet is designed for one-time use. Reusing it risks contamination that can throw off your calibration.

Q: How do I store the packets?
A: Keep them in a cool, dry place away from direct sunlight. This helps the solution stay stable until you use it.

Q: Why calibrate at pH 4.0?
A: Nutrient solutions for vegetative growth and flowering are usually mildly acidic. A pH 4.0 point is commonly paired with a second buffer for a two-point calibration that brackets your working range.