Aquatic Plant Fertilizer for Tanks & Water Features

When your aquarium and pond plants may benefit from feeding

In planted tanks with few or no fish, where little nutrient enters the water
Under bright lighting or added carbon dioxide, when plant demand outpaces supply
After large water changes, which remove dissolved nutrients
For tanks with inert gravel or sand rather than a nutrient-rich substrate
When plants are growing but slowly, and water quality is otherwise stable

Plant color and growth in an aquarium also depend on lighting, carbon dioxide, water changes and fish load, so dosing is one part of tank care.

Results you can see

Feeds foliage for deeper color and a brighter, more lively look.

Encourages fresh leaf and stem growth for a fuller, thriving plant.

Supports healthy, resilient roots that absorb nutrients more effectively.

Works for aquarium and pond plants

Anubias
Java Fern
Amazon Sword
Cryptocoryne
Vallisneria
Hornwort
Water Lilies
Dwarf Hairgrass

How to use

Add to tank water

1 tsp per 10 gallons of water, ideally in a high-flow area

High light tanks: 1-2 times a week
Add to tank water

1 tsp per 10 gallons of water, ideally in a high-flow area

Low light tanks: 2-4 times a month

What's inside

The 1-0.5-3 ratio is deliberately low in nitrogen and phosphate because aquatic plants feed from the water itself — excess nutrients feed algae before plants, so the goal is to supply just enough while keeping the water lean. The 1% nitrogen and 0.5% phosphate cover basic growth, while the 3% potash supports the vigor and color aquatic plants need, since potassium is depleted fastest under strong light. The nitrogen is nitrate nitrogen, taken up directly through the water column so it doesn't linger.

Beyond NPK: sea kelp (Ascophyllum nodosum) for natural growth compounds, plus 0.5% calcium and 0.25% magnesium and a full trace-micronutrient package — iron, sulfur, manganese, zinc, copper, boron, and molybdenum. Iron is the key nutrient for aquatic plants: it keeps leaves deep green and drives red coloration in many species, and it's used up quickly under bright light. The low overall concentration is intentional, letting you dose for plant health with a blend formulated to help minimize algae growth.

Label facts

NPK 1-0.5-3 with 0.5% calcium, 0.25% magnesium and 0.05% sulfur, plus iron, manganese, zinc, boron, copper and molybdenum.

Derived from kelp (ascophyllum nodosum), potassium phosphate, potassium nitrate, calcium nitrate, magnesium nitrate, boric acid, copper sulfate, ferric sulfate, manganese sulfate, zinc sulfate.

Store cool and dark. Guaranteed 12 months from purchase; keeps up to 2 years.

Frequently asked questions

How often should I dose aquatic plant fertilizer?

It depends on your light. Aquatic Plant Fertilizer is dosed at 1 teaspoon per 10 gallons of water: in a high-light tank, add it 1–2 times a week; in a low-light tank, 2–4 times a month. Bright light drives faster growth and faster nutrient use, so well-lit setups run through potassium and iron quickly, while dim tanks need far less. Add it near a high-flow area such as the filter outflow so it disperses, and dose to the actual water volume, allowing for the substrate and hardscape that displace water.

Can I use this with fish and invertebrates?

Aquatic Plant Fertilizer is formulated for the low nutrient levels aquatic plants need, so at 1 teaspoon per 10 gallons it is dosed by water volume rather than per plant. Keep to the dose and avoid sudden spikes, which stress any closed system. One point for shrimp and snail keepers: the formula carries copper at trace levels, and some invertebrates are copper-sensitive, so introduce it gradually and watch how your animals respond. Dose to water volume and never pour it directly onto livestock.

Will this cause algae in my tank?

Overdosing can, since algae use the same nutrients as plants, but in a planted tank algae is usually driven by an imbalance of light and CO2 rather than by fertilizer alone. Strong light without enough nutrients or CO2 for your aquarium and pond plants to use it is the classic trigger. Aquatic Plant Fertilizer is deliberately lean in nitrogen and phosphate so it feeds plants without loading the water column, and the nitrate nitrogen is taken up directly so it doesn’t linger; the blend is formulated to help minimize algae growth. Keeping algae down depends on balancing light, CO2 and nutrients together, along with regular water changes and steady dosing.

Do my aquatic plants need CO2 to use this?

No. Aquatic Plant Fertilizer works in low-tech tanks without added CO2 and in high-tech tanks with it; what changes is how often you dose. In a low-light setup without CO2, plants grow slowly and draw nutrients down gradually, which the 2–4 times a month schedule covers. In a high-light tank with CO2, growth is fast and potassium and iron deplete quickly, so you move to 1–2 times a week. CO2 accelerates growth but isn’t required. Match the frequency to your light level and to how fast your aquarium and pond plants are actually growing.

When will I see results?

New growth shows the difference first, and timing depends on light and CO2. Aquatic Plant Fertilizer supplies the potassium and iron aquatic plants draw down fastest under strong light, and new growth shows the difference first: stronger stems and better color, including the reds many species develop when iron is available. Fast-growing stem plants respond soonest; slower rosette plants and carpets take longer. Leaves already damaged won’t recover, so you’re feeding what comes next. Because results depend as much on light and CO2 as on nutrients, a balanced tank shows the clearest improvement.

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