--- product_id: 638201633 title: "- Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon" brand: "humboldts secret" price: "£126.15" currency: GBP in_stock: true reviews_count: 9 category: "Humboldts Secret" url: https://www.desertcart.co.uk/products/638201633-humboldts-secret-ph-down-for-plants-liquid-ph-adjuster-balancer store_origin: GB region: United Kingdom --- # Universal for soil, coco & hydro Highly concentrated formula Precise pH control 5.5-6.5 - Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon **Brand:** humboldts secret **Price:** £126.15 **Availability:** ✅ In Stock ## Summary > 🌿 Elevate your grow game with precision pH control—because your plants deserve the best! ## Quick Answers - **What is this?** - Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon by humboldts secret - **How much does it cost?** £126.15 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/638201633-humboldts-secret-ph-down-for-plants-liquid-ph-adjuster-balancer) ## Best For - humboldts secret enthusiasts ## Why This Product - Trusted humboldts secret brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Concentrated Efficiency:** Up to 25% stronger than competitors—use less, save more, and get lasting results. - • **Maximize Growth & Yields:** Support stronger roots, lush foliage, and abundant harvests across all plant types. - • **Optimize Nutrient Uptake:** Achieve perfect pH balance to unlock full nutrient potential and prevent deficiencies. - • **Trusted Pro-Grade Quality:** Formulated by expert growers with pure phosphoric acid—no dyes or additives. - • **Versatile for Every Grower:** Seamlessly compatible with soil, coco coir, DWC, NFT, and hydroponic systems. ## Overview Humboldts Secret pH Down is a professional-grade, highly concentrated liquid pH adjuster designed to quickly and accurately lower pH levels in soil, coco, and hydroponic systems. By maintaining an optimal pH range of 5.5 to 6.5, it enhances nutrient absorption, prevents deficiencies, and promotes vigorous plant growth from seedlings to harvest. This 2.5-gallon phosphoric acid solution is trusted by growers for its efficiency, versatility, and pure formulation, delivering consistent, robust results for all types of gardens. ## Description desertcart.com : Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon : Patio, Lawn & Garden Review: Humboldt ph dn - Works great and I use less then other brands per feeding Review: Quality product - Excellent product highly recommended!!! ## Features - Balance Your Grow Medium Fast: Our Humboldts Secret pH Down quickly and effectively lower pH in soil or coco to the optimal range for nutrient absorption. Prevents deficiencies and keeps plants stress-free while creating the right foundation for strong roots lush foliage and abundant harvests. - Fuel Stronger Healthier Growth: Maintain precise plant pH balance between 5.5 and 6.5 to prevent nutrient lockout and maximize vitality. Works for vegetables flowers and herbs in any medium helping your garden thrive from seedling to full production with consistent vibrant growth. - Highly Concentrated and Efficient: Just a small amount of our hydroponic pH down makes powerful lasting adjustments saving you time and money. Up to 25% stronger than some competitors this commercial grade formula ensures reliable results with minimal product use. - Versatile for All Growing Methods: Use Humboldts Secret pH Down in soil hydroponic systems like DWC and NFT coco coir or other grow mediums. Works seamlessly with your nutrient solution to support balanced feeding healthy stems and increased yields year round. - Expert Made Quality You Can Trust: Designed by growers for growers our concentrated pH down for plants uses high grade phosphoric acid and contains no dyes or additives. Proudly manufactured in California it delivers professional level results for every type of garden. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0CQ64MWBL | | Best Sellers Rank | #16,555 in Patio, Lawn & Garden ( See Top 100 in Patio, Lawn & Garden ) #143 in Hydroponic Nutrients & Additives | | Brand | Humboldts Secret | | Date First Available | February 16, 2023 | | Global Trade Identification Number | 00850058984117 | | Item Form | Liquid | | Item Weight | 24.6 pounds | | Item model number | 850058984117 | | Liquid Volume | 320 Fluid Ounces | | Manufacturer | HS Supplies, LLC | | Number of Items | 1 | | Package Dimensions | 13.8 x 8.7 x 7.2 inches | | Specific Uses For Product | Plant care, maintaining optimal pH level for plant growth | | UPC | 850058984117 | | Unit Count | 320.0 Fluid Ounces | ## Product Details - **Brand:** Humboldts Secret - **Global Trade Identification Number:** 00850058984117 - **Item Form:** Liquid - **Liquid Volume:** 320 Fluid Ounces - **Specific Uses For Product:** Plant care, maintaining optimal pH level for plant growth ## Images ![- Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon - Image 1](https://m.media-amazon.com/images/I/31duXay5jkL.jpg) ![- Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon - Image 2](https://m.media-amazon.com/images/I/51-OK99JMvL.jpg) ![- Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon - Image 3](https://m.media-amazon.com/images/I/516U2OV6odL.jpg) ![- Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon - Image 4](https://m.media-amazon.com/images/I/51KSjgoC81L.jpg) ![- Humboldts Secret pH Down for Plants | Liquid pH Adjuster and Balancer for Soil Coco Hydroponics | Concentrated Phosphoric Acid Solution Supporting Nutrient Uptake and Strong Growth | 2.5 Gallon - Image 5](https://m.media-amazon.com/images/I/51VVjb87NUL.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Humboldt ph dn *by R***N on November 4, 2025* Works great and I use less then other brands per feeding ### ⭐⭐⭐⭐⭐ Quality product *by R***E on December 29, 2025* Excellent product highly recommended!!! ### ⭐⭐⭐⭐⭐ Lowers Ph. *by S***N on October 7, 2025* I use this to lower the Ph in my water prior to watering my plants. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.uk/products/638201633-humboldts-secret-ph-down-for-plants-liquid-ph-adjuster-balancer](https://www.desertcart.co.uk/products/638201633-humboldts-secret-ph-down-for-plants-liquid-ph-adjuster-balancer) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-05-21*