Aquarium plant supplements: read the label before you mix

Separate nutrients from growth boosters

Some aquarium fertilizers supply nitrogen, phosphorus, potassium, and smaller amounts of other nutrients. Others leave out nitrogen and phosphorus. For example, Tropica’s Specialised Nutrition lists both, while its Premium Nutrition does not.¹² Read the actual label rather than choosing by bottle color or the word ‘complete.’

Keep those three things separate when comparing prices. A cheaper bottle is not necessarily cheaper to use.

Scale a stated dose to your water volume

Tropica lists 6 mL per 50 L weekly for Specialised Nutrition, with adjustment for plant needs.¹ For 40 L of actual water, the arithmetic is 6 × 40 ÷ 50 = 4.8 mL. This example applies to that product, not to another bottle or a dry powder. Use a marked measuring syringe rather than guessing a splash.

An ingredient list is not a DIY recipe

Seachem’s Flourish Advance label lists amino acids, mineral salts, and a small amount of plant hormones. The maker describes it as a growth enhancer.³ That tells you what this product contains. It does not establish that an amino-acid powder or kelp extract from a garden shop will have the same effect, or the same safety, in an aquarium.

Skip instructions such as ‘add a pinch.’ Without a known composition, concentration, water volume, and tested use, you cannot turn that pinch into a dependable dose. A result from orchids or a land-grown crop is not a dosing guide for submerged plants living with fish and shrimp.

Check the whole plant before adding boron

Boron is one of the trace nutrients listed in aquarium fertilizers such as Specialised Nutrition.¹ But the rule ‘boron never moves inside a plant’ is too simple. Brown and Hu’s experiments found that boron movement differed between tree species, including movement in species that transport the sugar alcohol sorbitol.⁴

That finding does not diagnose your aquarium plant. If new leaves look odd, check the plant’s requirements and your care routine before reaching for boric acid. Ask for help with photos of the whole plant, new growth, and older leaves, not just a close-up of the damaged tip.

Make one useful change at a time

Write down your light schedule, fertilizer product, dose, and water-change routine. Take a photo from the same angle before changing anything. This makes it easier to notice what actually changed instead of buying another bottle because one leaf looks worse.

If you choose a fertilizer, use one labeled for aquarium use and follow its current directions. Base the calculation on water volume, not the outside size of the glass. Tropica itself advises adjusting Specialised Nutrition to the plants’ needs rather than treating one dose as right for every tank.¹

For a low-cost start, choose plants that suit your existing setup using the plant finder. Compare a clear, suitable fertilizer with your current routine before adding optional boosters.

A few common questions

Sources

1. Tropica , Specialised Nutrition. Manufacturer’s nutrient declaration and dosing guidance.
2. Tropica , Premium Nutrition. Manufacturer states that this formula contains neither nitrogen nor phosphorus.
3. Seachem , Flourish Advance. Manufacturer’s ingredient list and product claims; not an independent comparison with DIY powders.
4. Patrick H. Brown and Hening Hu (1996) , Phloem Mobility of Boron is Species Dependent. Experiments on six tree species. They do not establish boron dosing for aquarium plants.