Advanced Nutrients® pH Down, 1 Liter Fine-tune hydroponic nutrient solution with Advanced Nutrients pH Down, a concentrated phosphoric-acid water pH adjuster. Use small amounts to gradually lower solution pH and help keep nutrients available to your plants. Why growers use pH Down Concentrated formula for precise pH adjustments Designed for hydroponic nutrient solutions and continuous-feed systems Works with aeroponics, drip irrigation, NFT, flood and drain, and deep water culture Recommended hydroponic pH range in the product directions: 5.5–5.8 One-liter bottle for home gardens and regular reservoir maintenance How to use Check your mixed nutrient solution, add a small amount of pH Down, mix thoroughly, and test again. The product directions recommend checking pH daily and adjusting as needed. Follow your nutrient program and local handling guidance.