ESSENTIALS pH Buffer 4&7 really are essential. Growers should keep these on stand by to regularly calibrate their pH meters. General Information Proper maintenance of your pH meter is essential for delivering accurate results each time. If your meter is not calibrated correctly, you run the risk of feeding an overly acidic or alkaline solution to your plans which can result in irreversible damage. We have found that ESSENTIALS pH Buffer 4 & 7 deliver consistent results every time. Benefits Consistent solution Used for calibrating pH meters How to Use Pour a small amount into a container and hold your pH meter in the solution. Follow necessary instructions provided with your pH meter regarding calibration.