Guide
Aquarium plant fertilizer
NPK, micronutrients, and dosing without fueling algae.
- Macros: Nitrogen (N), phosphorus (P), potassium (K) — plants need all three in balance with light and CO₂.
- Micros: Iron, manganese, etc. — usually dosed in trace mixes.
- Algae: Overdosing or light without CO₂ balance can trigger algae; start low and adjust using plant growth as feedback.
Liquid vs root tabs
Liquid fertilisers feed the water column; root tabs suit heavy root feeders (e.g. swords). Many tanks use both.
Reading plant signals
Yellowing leaves, holes, or stunted growth suggest different deficiencies — match to a reputable deficiency chart. See potassium deficiency.
CO₂ and light
High light + high nutrients without stable CO₂ often causes algae. Keep the system balanced — not every tank needs maximum fert dosing.
Log nitrate and fert schedules with App-aquatic.
Get the free appDo I need fertilizer if I have fish waste?
Often not enough for demanding plants; heavy plantings usually need supplementation.
Can fertilizer cause algae?
Yes if combined with excess light or imbalanced CO₂ — dose to plant demand, not guesswork.
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