ADVANCED NUTRIENTS - PH PERFECT MICRO - 20LGMB fertilizer contains PH PERFECT technology which definitively eliminates the hassle of having to measure manually the Ph at each administration of the nutrient solution. In practice, if the acidity of your water measures between 4. 5 and 8. 5 (which is more or less the pH of all commonly used water) this technology automatically adjusts your pH and always keeps it stable: this means you no longer have to manually fix it, buy acids to raise or lower