Signs of deficiencies

Signs of deficiencies:

Symptoms	Cause
Old leaves turn yellowish/ red	Nitrogen deficiency
Leaf loss and small dead areas	Phosphate deficiency
Black/ brown leaves, plants die	Excess phosphates
Yellow spots on old leaves and yellowish margins on younger leaves	Potassium deficiency
Yellowish margins on young leaves with deformat	Calcium deficiency
Yellow spots on old leaves while veins stay green	Magnesium deficiency
Young leaves turn yellow	Sulfur deficiency
Yellowing leaves starting from the tip then become transparent	Iron deficiency
Yellow spots between the veins, margins and tips	Zinc deficiency
Plant stays small slow or now growth white deposits on leaves (calcium)	CO2 deficiency
Fish gasp for air on surface	Excess CO2
Sluggish fish no plant growth	Oxygen deficiency
Plants stop growing/ black roots	Substrate problem

Iron Deficiency

This is a classic sign of iron deficiency in plants. Iron is a MICROnutrient and although thought for many years that iron(as well as phosphates p04) cause algae it does if to much is in the tank and other nutrients are not balanced.

Potassium Deficiency

This is a classic sign of potassium deficiency in plants. If potassium is not available to plants the start to disintegrate showing holes and leaves go very brittle.

c02 deficiency

c02 deficiency shows up as black markings on java fern as shown here.