Description
Bring a High-pH Feed Back Into the Sweet Spot
Emerald Harvest pH Down is a premium pH acidifier based on phosphoric acid (40–45%), made to lower the pH of a nutrient solution or growing medium that has drifted too alkaline. Emerald Harvest formulates it as a buffer around a weak acid, so small additions bring a reservoir into the maker's recommended pH 5.5–6.3 range without a sudden swing that stresses roots or the beneficial microbes in the root zone. It is made for hydroponic systems, works in any growing medium where the pH reads too high, and pairs with Emerald Harvest pH Up for corrections in either direction.
Key Benefits
- Phosphoric acid base – a 40–45% phosphoric acid solution that lowers pH quickly and predictably.
- Gentle on roots and microbes – a weak-acid buffer, used in small quantities, that avoids sudden swings and keeps beneficial bacteria colonies stable.
- Prevents nutrient lockout – holding pH in range keeps iron, manganese and the other essential elements available.
- Concentrated – a little moves a full reservoir, so it goes a long way.
- Long shelf life – 3 years or more under normal storage.
Nutrient Lockout From a High pH
When a nutrient solution or growing medium drifts above about pH 6.5, some elements, iron and manganese in particular, become partly or wholly locked out. Leaves can yellow, spot, curl or die back and growth slows even though the feed is right on paper, and stressed plants are more open to pests and disease. Those symptoms have other causes too, so test first; if the pH reads high, a small dose of pH Down restores the balance and nutrient uptake gets back on track.
How to Use
- Mix first: add every base nutrient and additive to the water and stir before measuring the pH with a calibrated meter.
- Dose in small steps: add a very small amount of pH Down, stir thoroughly and re-test after each addition.
- Target: pH 5.5–6.3 for the nutrient solution and growing medium, with 5.8–6.3 as Emerald Harvest's sweet spot for hydroponic gardens.
- Soil and coco: correct the pH of the feed solution before watering, as part of your usual routine.
- Never mix it neat with pH Up or concentrated nutrients; always add it to the diluted solution.
- Safety: it is corrosive – wear gloves and eye protection, keep it in its original container, sealed, locked away, in a cool, dry place out of direct sunlight.
Technical Specifications
- Brand: Emerald Harvest
- Type: pH Down – premium pH acidifier
- Active ingredient: Phosphoric acid, 40–45%
- Product pH: 2
- Appearance: Clear, odourless liquid
- Density: 1.32 kg/L at 20°C
- Target range: pH 5.5–6.3; sweet spot 5.8–6.3 for hydroponics
- Suitable for: Hydroponic systems and any growing medium where the pH is too high
- Shelf life: 3 years or more under normal storage
- Hazards: Causes severe skin burns and eye damage; may be corrosive to metals
Frequently Asked Questions
How much pH Down should I add?
There is no fixed dose, because it depends on your water and the nutrients in it. Add a very small amount, stir well and re-test, repeating until the solution reaches pH 5.5–6.3.
Can I use it with soil and coco as well as hydro?
Yes. Adjust the pH of the feed solution before you water, as you would for a hydroponic reservoir.
Does it work with other nutrient brands?
Yes. It lowers the pH of any nutrient solution. Emerald Harvest base nutrients are pH buffered, so with their range you will usually need less.
Is it safe to handle?
It is a corrosive acid, so wear gloves and eye protection, avoid splashes and store it sealed in its original container, locked away from children.
Works Well With
