Potassium or Micronutrient Deficiency

Holes or see-through patches in otherwise healthy-looking leaves usually point to a potassium or micronutrient deficiency rather than disease or pests. A comprehensive liquid fertilizer typically resolves it within a couple of weeks.

Why this happens

• Low potassium or micronutrients relative to how fast the plant is growing.
• Common in tanks that dose nitrogen and phosphorus but skip a comprehensive micronutrient supplement.

What to do next

1. Switch to or add a comprehensive liquid fertilizer that includes potassium and micronutrients, not just nitrogen and phosphorus.
2. Dose consistently on a regular schedule rather than occasionally.
3. Trim affected leaves — the holes won't heal, but new growth should come in healthy once the deficiency is corrected.
4. Expect improvement within about two weeks of consistent dosing.

Frequently asked questions