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All problems
Moderate
Nutrient Deficiency

Yellow new growth (tops pale, veins still green)

New top leaves emerge pale yellow with green veins — a 'stained glass' look.

Commonly affects: Tomatoes, Peppers, Cucumbers, Strawberries

What you'll see

  • Newest leaves yellow between the veins
  • Veins remain dark green
  • Older leaves look fine
  • Growth slows at the top

Likely causes

  • Iron deficiency — usually a pH lock-out, not a true shortage
  • High pH can reduce iron availability; the effect depends on chelation and water chemistry
  • High phosphorus or zinc levels can also block iron
  • Cold root zone (<16 °C) reduces iron uptake

How to fix it (step by step)

  1. 1Correct tank pH to 5.5–6.0 first, monitor new growth, and investigate other causes if symptoms persist
  2. 2If symptoms persist, inspect source water and roots and seek crop-specific advice before changing the feed
  3. 3Warm the reservoir to 18–22 °C if it has been cold

Stop it happening again

  • Keep pH between 5.5 and 6.0 at all times
  • Use MICRO every feed — it carries the chelated iron and trace elements
  • Insulate or use a heater for outdoor reservoirs in winter

Recommended products

Part 1 · Use with GROW and BLOOM

NaO MICRO

Calcium and micronutrients · Part 1 of 3

View product

Need a second opinion?

Share dated photos, root observations, water readings and your mixing record so our team can assess the problem. Visual symptoms alone do not confirm a diagnosis.

Confirm the cause before treating the crop

Collect observations that distinguish possible causes

Record the first appearance of symptoms, the affected plants and whether old or new tissue is involved. Inspect roots, delivery and visible pests. Compare a healthy plant nearby. Record pH, EC, temperature and recent changes. Several causes may act together; the symptom title is a starting point, not a confirmed diagnosis.

Verify calibration and the complete mixing record. Product links explain nutrient roles; they are not instructions to use one bottle alone. Record your correction and assess subsequent growth because damaged leaves and fruit may not recover.

Escalate safely

Rapid wilting, collapse or spreading root symptoms need prompt checks of flow, oxygen and hygiene. Protect unaffected plants where practical and seek qualified diagnosis. Treatments must be registered for their intended crop and use and applied according to label, including harvest intervals.

When asking for help, provide dated root and leaf photos, water readings and mixing records. Do not combine nutrient changes with disinfectants or pesticides without compatibility advice. An online guide cannot confirm a pathogen or prescribe a universal chemical treatment.

Further reading

These sources support general cultivation guidance, not verified Nana Organics product performance. Current NaO instructions take precedence over another brand’s feeding schedule.