How often should I fertilize aquarium plants?
Written by
Kailani Okoro
Reviewed by
Prof. David Walsh, Ph.D.Fertilization schedules will vary according to the type of plant as well as where it is on its growing curve. Liquid fertilizers are more effective during water changes. Root tabs will keep heavy feeders going for a quarter, while red plants require their weekly dose of iron, and so on. Providing the nutrient delivery system with what it needs at the right time will prevent deficiencies.
Liquid Fertilizers
- Apply daily after 25% water changes
- Dose according to plant density
- Best for epiphytes and floating plants
Root Tabs
- Replace every 3 months for heavy root feeders
- Place near Amazon Sword and Cryptocoryne
- Provide slow-release nutrients
Specialized Supplements
- Iron weekly for red plants like Alternanthera
- Potassium bi-weekly for fast-growing stems
- CO2 during daylight hours for demanding species
New plants require rather different treatment from established ones. Begin with half a dose of liquid fertilizer daily, and after two weeks, increase to full strength. Plants with mature roots will not require so many stimulants and adjuncts to growth; regulate the treatment according to the appearance of growth and colour of the foliage.
Check plants for symptoms of nutrient deficiency. Yellow leaves indicate a nitrogen deficiency. Holes in the leaves indicate a potassium deficiency. Stunted growth suggests a phosphate deficiency. Apply fertilizer right away after the first symptoms appear. Use your water test each week to assess the effectiveness of your adjustments.
Climate affects fertilization needs. In the warmer months, plants and algae grow quickly, which requires more nutrients. Use less nursery during winter when everything slows down. You should also consider tank maturity. New tanks require significantly less fertilization than established tanks.
Read the full article: 15 Essential Aquarium Plant Types for Beginners
