Common Symptoms of Nutrient Deficiencies (and Excesses)
When consulting this list of deficiences and excesses, please remember that many symptoms are possible, and that the ones given here should only be used as a clue in tracking down a problem in the planted tank, not as an absolute diagnosis.
Carbon dioxide deficiency — Small leaf size, slow growth, rough whitish deposits on plant leaves (from biogenic decalcification).
Nitrogen deficiency — Old leaves turn yellow, or occasionally reddish, due to the production of anthocyanin (this reddish pigment is only seen in tanks with very strong light levels).
Phosphorus deficiency — The symptoms here can be similar to those in nitrogen deficiency. There is leaf loss and small dead areas on older leaves.
Potassium deficiency — Yellow spots on older leaves, and withering of leaf tips and margins (also on older leaves first).
Calcium deficiency — Young leaves often have yellow margins. New growth is often deformed.
Magnesium deficiency — Yellow spots, first on older leaves. It can look very similar to iron deficiency.
Sulphur — Yellowing of the new leaves first. Red color from the production of anthocyanin possible in strong light.
Iron deficiency — Yellowing leaves, first at the growing tip. Leaves become brittle and transparent before they eventually disintegrate. Fast-growing plants, like Hygrophila sp., will show iron deficiency the fastest.
Manganese deficiency — Yellow areas between veins, while the veins themselves remain green. The tissue between the veins then dies, producing elongated holes in the leaves. These symptoms can also be seen in the presence of excess iron because this condition can block the uptake of manganese.
Copper deficiency — The tips of the leaves die and margins wither. Excess copper will kill a number of plants, including Vallisneria, Ludwigia, Sagittaria and others.
Zinc deficiency — Yellow areas appear between the veins, on the margins and at the leaf tip on older leaves.
Boron deficiency — Growth tips die. The plant produces side shoots, but these aslo die quickly.
Molybdenum deficiency — Yellow spots between veins on old leaves first. This is followed by brown areas along leaf margins. Flowering is inhibited.
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