General Hydroponics pH 4.01 Calibration Solution Size:1 Quart Use 5 ml per gallon

Use 5 ml per gallon for mature plants

such as coco and rockwool

The outside edges are grounded round

used as a top dress or steeped to make a potent foliar tea

Expect drastic reductions in the use of your base nutrients and other additives by as much as 50%

General Hydroponics pH 4.01 Calibration Solution Size:1 Quart Use 5 ml per gallonGeneral Hydroponics uses the highest quality reference solutions, allowing growers to calibrate many popular brands of PH, EC and TDS meters (NaCl scale or the 442 scale). General Hydroponics technicians check each batch to ensure that our solutions are precisely calibrated and yield reliable readings each time they are used. Free Standard shipping