GROWERS ARK COCO GROW H/W 5 LITRE

Description

Growers Ark Coco Grow Hard Water 5 Litre is a professional coco coir vegetative-stage base nutrient formulated for use with hard tap water that we have been supplying to UK growers since 2017. Part of the Growers Ark range developed by experienced UK growers for UK growing conditions, the Hard Water formulation accounts for the elevated calcium, magnesium and bicarbonate content of hard tap water prevalent across much of England — preventing the nutritional imbalances that result from using standard or soft-water-formulated nutrients in hard water areas without adjustment.

Hard Water Nutrient Formulation: Why It Matters in the UK

Mains tap water EC across much of southern England, the Midlands and East Anglia commonly reads 0.3–0.7 mS/cm from dissolved calcium bicarbonate and magnesium sulphate. This represents a significant pre-existing mineral load that a grower must account for when targeting a reservoir EC of 1.2–1.8 mS/cm for vegetative growth. A standard nutrient designed for soft or RO water used in hard water will deliver excess calcium and magnesium (from tap water background plus full nutrient dose), waste EC headroom on elements already present in abundance, and potentially create competition-based deficiencies of potassium and trace elements through cation imbalance. Growers Ark Coco Grow Hard Water reduces calcium and magnesium inputs accordingly and adjusts the full mineral profile to work with the pre-existing water chemistry, delivering a genuinely balanced final nutrient solution at the correct total EC for coco vegetative growth.

EC Management, Feed Rates and Transition to Bloom

Test tap water EC before preparing nutrient solution. Use at 3–5 ml per litre as a starting point, adjusting to achieve target total reservoir EC of 1.0–1.6 mS/cm for vegetative growth. Maintain pH 5.8–6.2 in coco. Transition to Growers Ark Coco Bloom Hard Water at the start of flowering, introducing over 1–2 weeks by blending grow and bloom nutrients in changing ratios. Supplement with SHOGUN CalMag at 0.5–1 ml per litre if plants show calcium or magnesium symptoms at any growth stage.