Acidity and alkalinity are extremely important factors in your crop's water and root zone. Ideal pH for your plants is 5.8-6.3. A pH reading out of that range indicates conditions that very much decrease your plants' ability to take in hydroponics nutrients, grow well, and produce large harvests.If pH is too extremely out of range, your plants may die!We advise you to do daily monitoring and adjustment of pH. Whether you're using hydroponics, sphagnum moss, coco coir, rockwool, aeroponics, soil, or other types of gardening technology, you need a pH meter and pH adjustment formulas like Advanced Nutrients pH Down and pH Up. Here's how to use pH Down: Get yourself a pH meter and read your root zone and nutrient water pH daily. You'll usually find that pH needs to be adjusted. If you don't adjust pH to optimum levels, your plants will grow slowly, produce little bitty harvests, or maybe die. Advanced Nutrients pH Down is a professional, pharmaceutical grade version of phosphoric acid that immediately lowers hydroponics pH without harming plants. So adjust pH as needed with our pure, safe ph Down. Or, if your pH is too low, use Advanced Nutrients pH Up.Your plants will respond with rapid growth and very high yield. Our 100% money back guarantee assures you that our pH adjustment products are the best available.