The Best Aquatic Plant Fertilizers in 2022

Taking care of aquatic plants is a careful balancing act – even if you can’t see it. Aquatic plants need a careful balance of different minerals and getting that balance right is essential to their growth. Luckily, that’s where aquatic plant fertilizers come in handy.

Different plants need different things. Therefore, you’ll need to adjust your purchases based on what plants you currently have. For instance, red plants often need more iron to maintain their red coloration (otherwise, they often become a dull green).

Below, we’ve listed different types of fertilizers that are better for certain plants. Based on this information, you should be able to select the products you need for your aquarium.

A-Z-Animals Top Picks for Aquatic Plant Fertilizers

#1 API Leaf Zone Freshwater Aquarium Plant Fertilizer – Best Overall

If you’re looking for a generalized fertilizer, then Leaf Zone is for you. It includes a general formula of everything your average aquarium plant needs. Therefore, it is great for those new to the aquarium-keeping world and those that don’t feel like formulating their own fertilizing schedule.

In other words, this is an easy, effective option.

It contains iron to prevent yellowing and help maintain plants’ proper color. Leaf Zone also includes potassium, which helps maintain cell pressure and promote photosynthesis.

Use this formula in freshwater only. You can use it in aquariums containing fish, as it is completely safe for most. It absorbs rapidly into plant leaves.

Best Overall

API Leaf Zone Freshwater Aquarium Plant Fertilizer

• Generalized fertilizer
• Absorbs rapidly into plant leaves
• Easy, effective option
• Iron prevents yellowing

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#2 API CO2 Booster Freshwater Aquarium Plant Care – Best CO2 Booster

Just like plants above the surface, aquatic plants need CO2 to thrive. Otherwise, they literally won’t be able to breathe. In most cases, the fish will release CO2 into the water and provide your plants with enough carbon components. However, if you don’t have fish in your aquarium (or don’t have enough), then your plants may benefit from some extra.

Unlike most CO2 boosters, this one will not alter the pH of your tank. Therefore, it is safe to use with most fish and plants. You can use it daily as needed. Combine it with other CO2 systems for maximum efficiency.

Because CO2 is absolutely necessary for the survival of your plants, you’ll likely find yourself needing to use this supplement as well as a few others.

Best CO2 Booster

API CO2 Booster Freshwater Aquarium Plant Care

• Aquatic plants need CO2 to thrive
• Will not alter the pH of your tank
• Safe to use with fish
• For use in freshwater aquariums

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#3 API Root Tabs Aquarium Plant Fertilizer – Best Root Tabs

Some plants simply due better with root tabs – and they are often easier for beginners to you. You may also want to use root tabs if you have sensitive fish in your tank, since they may be unable to withstand adding liquid supplements.

Using these tabs is simple. Add tabs to the gravel about once a month. They will dissolve and be absorbed by your plant’s roots. These tabs contain iron, as well as a few other essential nutrients.

Furthermore, you can use these tabs when planting new plants or slide them underneath existing plants.

However, the only downside is that these tabs only work with plants that are attached to the gravel at the bottom of your plant’s aquarium. Plants that attach to rocks and branches cannot access the nutrients.

Best Root Tabs

API Root Tabs Aquarium Plant Fertilizer

• Very simple to use
• Add to roots about once every month
• Use this with sensitive fish who cannot stand liquid additions
• Contain iron and essential nutrients

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#4 Fluval Plant & Shrimp Stratum Plant Care – Best for Plants and Shrimp

As the name suggests, this substrate is perfect for plant and shrimp care. It is one of the few aquatic plant fertilizers that keep shrimp in mind, in fact.

We recommend it for freshwater aquariums that plan on having shrimp. The organic discoloration of the substrate helps keep baby shrimp safe, as it allows them to blend in more readily.

Made with rich volcanic soil, this substate does not discolor water. It encourages the flourishing of nitrifying bacteria, which help promote a mildly acidic pH. Be sure that your plants and fish prefer this pH before selecting this substrate.

Best for Plants and Shrimp

Fluval Plant & Shrimp Stratum Plant Care

• Perfect for plant and shrimp care
• Made with rich volcanic soil
• Promote a mildly acidic pH
• Baby shrimp blend in perfectly with the color of the substrate

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#5 Fluval Plant Micro Nutrients Plant Care – Best with Micro Nutrients

If you’re looking to add micronutrients to your substrate, we highly recommend this micronutrient supplement by Fluval. It provides aquatic plants with all the micronutrients they need to thrive. Plus, we liked that it contains high levels of iron and very effective sources of vitamin B, which are necessary for cellular metabolism.

With these micronutrients, your plants are more likely to exhibit a bright color and grow strong root systems. We highly recommend this formula for those with vibrantly colored plants, as these nutrients will help those colors remain.

All of the nutrients are chelated to promote absorption. Plus, unlike similar formulas, the chelation of these minerals prevents oxidation and precipitation, which can harm your plants and fish.

Best with Micro Nutrients

Fluval Plant Micro Nutrients Plant Care

• Micronutrient supplement
• Contains iron and vitamin B, necessary for cellular metabolism
• Especially recommended for vibrantly colored plants
• Nutrients are chelated for better absorption

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#6 Dennerle NPK Booster Macro-Fertilizer – Best for Aquariums with No Fish

Naturally, plants and fish are designed to balance each other out. However, if you don’t have any fish in your aquarium (or very few fish), then you need to add some of the nutrients that the fish typically would. Luckily, that is exactly what this fertilizer is designed to do.

We highly recommend it for heavily planted aquariums that have few to no fish. It helps fill the gaps that the lack of fish leaves.

Specifically, it is formulated with nitrate, phosphate, and potassium. All of these are balanced to support the health of most plants. However, we do recommend keeping in mind what plants you have. After all, not all plants will like this balance of nutrients.

Furthermore, we found that this fertilizer helps balance out excessive CO2 fertilization. Therefore, if you’re also adding CO2, you can avoid some of the negative effects by also utilizing this formula.

Best for Aquariums with No Fish

Dennerle NPK Booster Macro-Fertilizer

• Recommended aquariums that have few fish
• Add nitrate, phosphate, and potassium
• Balance out excessive CO2 fertilization
• Specifically designed for fast-growing plants

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#7 Dennerle E15 FerActiv Iron Aquatic Plant Fertilizer – Best for Iron

If you just want to add some extra iron to your aquarium, we recommend selecting this aquatic plant fertilizer. We especially recommend this fertilizer for those with red or unusually colored plants, as the iron helps them maintain their red coloration. However, it can also help green plants maintain a lush, green color.

For those with yellow or glassy plants, this extra iron may be exactly what you need.

We like that this formula provides an instant boost of iron to the aquarium, as well as a slower, time-release effect. Therefore, you don’t have to worry about continuously adding iron.

Best for Iron

Dennerle E15 FerActiv Iron Aquarium Plant Fertilizer

• Add extra Iron for beautiful color
• Immediate boost plus a slower, time-release effect
• Ideal for freshwater plants
• Will promote lush, green vegetation

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#8 Dennerle S7 Vitamix Vital Substances Aquarium Plant Treatment – Best General Fertilizer

This aquarium fertilizer provides just about everything you need for the average aquarium. It includes boron, iron, and manganese, which are generally what most plants need in a fertilizer.

This fertilizer ensures that your plants have everything this need for quite a while, as the formula is extremely concentrated. Therefore, you don’t have to use it a lot. When you’re looking at the price, consider this, as well.

We liked that this fertilizer promotes healthy growth in most plants. As a generalized formula, you can expect that this fertilizer can be used for most purposes.

Best General Fertilizer

Dennerle E15 FerActiv Iron Aquarium Plant Fertilizer

• Includes boron, iron, and manganese
• Extremely concentrated, so you use a little at a time
• Promotes healthy growth
• Prevents yellow, glassy leaves

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Choosing the Best: What to Look For

There are tons of different aquatic plant fertilizers out there. However, many of them only contain certain ingredients. Therefore, you have to choose the right one for your plant.

When purchasing an aquatic plant fertilizer, you need to consider the ingredients, longevity, and price.

Ingredients

Aquatic plants need all sorts of different things. Therefore, fertilizers can have a huge variety of different ingredients as well. Some of them are only iron, for instance. Others are a mix of many different nutrients, including phosphorus. There are also CO2 supplements.

You need to carefully choose the best supplement for your tank, based on your plants and environment.

Longevity

Different fertilizers have different longevities. Some of them release instantly, allowing them to instantly feed the plants. Others have a delayed response. Therefore, they don’t always get absorbed by the plants.

You should carefully consider which option you need for your aquarium. Often, slow-release formulas are the best options.

Price

Luckily, aquatic plant fertilizers are not terribly expensive. You can typically find them for only a few dollars. Usually, they’re around $15 to $35. Be sure to take a look at the amount you need to use for them to be effective. A larger dose will lead to the product costing more.

Verified Review: User Experience

As long as you purchase the correct aquatic plant fertilizers for you, then most users were quite happy with their experience. For instance, Leaf Zone tends to do quite well for plants. Many users stated that their “plants look amazing after two weeks of use.” Others generally loved the API brand, which is one reason why we included so many options in this review.

However, some users seemed to have mismatched their plants’ needs. Some of them claimed that Leaf Zone wasn’t “all that their plant needs,” which could very well be the case. For this reason, we highly recommend that you consider what your plant actually needs before making a purchase.