Best Liquid Fertilisers for Planted Aquariums
Liquid fertiliser is essential for healthy plant growth in aquariums — even with nutrient-rich substrate, plants absorb a significant portion of their nutrition through the water column via their leaves. This best liquid fertiliser planted aquarium guide from Gensou Aquascaping at 5 Everton Park compares the top products available in Singapore.
All-in-One vs Separate Dosing
All-in-one fertilisers contain macro and micronutrients in a single bottle. You dose one product and everything is covered. Simple, convenient and suitable for most hobbyists. The trade-off is less control over individual nutrient levels.
Separate dosing uses individual products for macronutrients (nitrogen, phosphorus, potassium) and micronutrients (iron, manganese, boron, etc.). This allows precise control and customisation — for example, boosting iron for red plants without changing other levels. More complex but preferred by advanced aquascapers and those running demanding high-tech tanks.
APT Complete ($18–$25)
Made by 2Hr Aquarist (a Singapore-based company), APT Complete is arguably the best all-in-one fertiliser in the hobby. It contains all macro and micronutrients in carefully balanced ratios. One pump per 60 litres daily is the standard dose. The formula is specifically designed for planted aquariums and is shrimp-safe (no copper above trace levels). APT Zero is available for tanks with fish that provide sufficient nitrogen and phosphorus through waste — it supplies only potassium and micronutrients. Widely available at Singapore aquarium shops and directly from 2Hr Aquarist.
Tropica Premium Nutrition ($15–$20)
A micronutrient-only fertiliser from the Danish plant experts. It provides iron, manganese and other micronutrients but no nitrogen or phosphorus — relying on fish waste for those. Ideal for lightly planted, fish-stocked tanks. Tropica Specialised Nutrition is the full macro + micro version for heavily planted tanks. Both are available in Singapore and trusted globally for quality and consistency.
Seachem Flourish Series ($12–$18 per bottle)
Seachem offers the most comprehensive range of separate products: Flourish (comprehensive micro), Flourish Iron, Flourish Nitrogen, Flourish Phosphorus, Flourish Potassium and Flourish Excel (liquid carbon). This modular approach gives maximum control but requires managing multiple bottles and dosing schedules. The Flourish Comprehensive is a decent all-in-one for low-tech tanks. Available at most Singapore aquarium shops.
EI Dosing (Dry Salts)
Estimative Index dosing uses dry chemical salts — potassium nitrate (KNO₃), monopotassium phosphate (KH₂PO₄), potassium sulphate (K₂SO₄) and a micronutrient mix like CSM+B. You dissolve these in water to make your own stock solutions and dose according to the EI schedule. By far the cheapest method — a year’s supply costs $10–$20 in dry salts versus $100+ in commercial liquids. Requires an initial learning curve and a kitchen scale. Dry salts are available from chemical suppliers on Shopee and Lazada.
Choosing the Right Fertiliser
Low-tech, lightly planted: Tropica Premium or Seachem Flourish Comprehensive. Micro-only is usually sufficient.
Moderate planted with fish: APT Complete or Tropica Specialised. All-in-one with balanced macros and micros.
High-tech, heavily planted: APT Complete at higher doses, or EI dosing for maximum control and lowest cost.
Shrimp tanks: APT Complete (confirmed shrimp-safe) or Tropica Premium. Avoid products with copper warnings.
Dosing Tips
Dose consistently at the same time daily — consistency matters more than exact amount. Start at the recommended dose and adjust based on plant response. If algae increases, reduce the dose or increase water changes. If plants show deficiency symptoms despite dosing, increase gradually. Always dose after water changes to replenish nutrients removed with old water. Store fertiliser bottles away from light and heat to maintain potency.
Related Reading
emilynakatani
Still Have Questions About Your Tank?
Drop by Gensou Aquascaping — most walk-in questions get answered in under 10 minutes by someone who has set up hundreds of tanks.
5 Everton Park #01-34B, Singapore 080005 · Open daily 11am – 8pm
