Add 250mL deionized water (or distilled water) to the beaker. Great for testing pH balance of drinking water, pool, aquarium, RO system, Spa, or hydroponics. 5x 4.01 solution (potassium hydrogen phthalate).
5x 6.86 solution (mixed phosphate). Great for testing pH balance of drinking water, pool, aquarium, RO system, Spa, or hydroponics. 5x 4.01 solution (potassium hydrogen phthalate). Add 250mL deionized water (or distilled water) to the beaker.