Iron Deficiency (Chlorosis)
Iron is the quintessential micronutrient and the engine of chlorophyll production. Because Iron is immobile within the plant, it cannot be recycled from old tissues. Therefore, a sudden drop in water column iron levels will exclusively strike the brand new growing tips.
Plant profile
Resolution Difficulty
Observe and distinguish
Identification and context
Signs and distribution
Apical and Interveinal Chlorosis
New leaves emerge pale lemon yellow or, in acute cases, completely stark white and ghostly. As with magnesium deficiency, the tissue between the veins fades first, leaving a web-like green vein structure against a white background. However, unlike magnesium (which hits the bottom of the plant), iron chlorosis exclusively hits the extreme top growing shoots. Over time, the white leaves disintegrate and the growing tip dies.
Affected tissue and growth
Apical and Interveinal Chlorosis
New leaves emerge pale lemon yellow or, in acute cases, completely stark white and ghostly. As with magnesium deficiency, the tissue between the veins fades first, leaving a web-like green vein structure against a white background. However, unlike magnesium (which hits the bottom of the plant), iron chlorosis exclusively hits the extreme top growing shoots. Over time, the white leaves disintegrate and the growing tip dies.
Physiology or exposure
Iron is the quintessential micronutrient and the engine of chlorophyll production. Because Iron is immobile within the plant, it cannot be recycled from old tissues. Therefore, a sudden drop in water column iron levels will exclusively strike the brand new growing tips.
Verify before intervening
Confirmation and decisions
Differential diagnosis
Compare sign distribution, leaf age, mechanical damage, emersed-to-submersed adaptation, algae, pests and multiple concurrent deficiencies.
How to verify
Confirm with a photographic timeline, repeated measurements and one controlled change at a time; an isolated leaf sign does not automatically identify the cause.
Proportionate actions
Management and monitoring
What to do now
Stabilize light, CO₂, temperature and water quality; remove only decaying tissue. Avoid concentrated corrections or several simultaneous changes.
Controlled correction
Use the Correct Form of Iron
If your pH is acidic (< 7.0), standard EDTA iron fertilizers are fine. If your pH is > 7.2, you must seek out stronger chelators like DTPA or EDDHA. Some liquid fertilizers (like Seachem Flourish Iron) use Ferrous Gluconate; this is instantly absorbable but lasts only 12-24 hours in the tank, requiring daily dosing. Aim for a maintained 0.1 - 0.2 ppm of Iron in the water column.
New-growth response
Dose your iron or trace element mix daily or every other day rather than in one giant weekly dump. The intense lighting and high oxygen in planted tanks degrade iron extremely quickly. Daily micro-dosing ensures constant availability.
Prevention
Dose your iron or trace element mix daily or every other day rather than in one giant weekly dump. The intense lighting and high oxygen in planted tanks degrade iron extremely quickly. Daily micro-dosing ensures constant availability.
When to escalate
Escalate if deterioration is rapid, involves the rhizome or stem, produces foul odor, or coincides with animal distress or detectable ammonia/nitrite.