Have you ever seen an aquarium full of lush, healthy plants and thought you could never pull it off? Well, you’re in luck! Creating a full, planted tank is not as difficult and intimidating as it seems. All you need is light, time, and a solid aquarium plant fertilizer. These reviews of the 6 best aquarium plant fertilizers will help you find one that will work perfectly in your tank, helping you create the lush planted tank of your dreams.

If you have goldfish, cichlids, or even dojo loaches, then you may have to get creative to keep plants safe long enough to grow but providing a fertilizer that is appropriate for your plants will help you achieve this. The first step is identifying whether your plants can pull nutrients from the water column or from the substrate so you know if you need liquid fertilizer or root tabs.

There are aquarium plant fertilizer options available for indoor and outdoor use and for water column and root feeder plants, so you have lots of great options when it comes to aquarium plant fertilizers, no matter the setup of your tank or pond.

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A Quick Comparison of Our Favorites

Image Product Details
Best Overall
Winner
Flourish Freshwater Plant Supplement Flourish Freshwater Plant Supplement
  • Available in 5 bottle sizes from 50-1000ml
  • Includes phytohormones to improve growth
  • Can be safe for invertebrates if dosed appropriately
  • Best Value
    Second place
    API Leaf Zone Freshwater Aquarium Plant Fertilizer API Leaf Zone Freshwater Aquarium Plant Fertilizer
  • Invertebrate safe
  • Contains iron to prevent yellowing of leaves
  • Contains potassium to boost colors and growth
  • Premium Choice
    Third place
    NilocG Aquatics Aquarium Fertilizer Shrimp Specific ThriveS NilocG Aquatics Aquarium Fertilizer Shrimp Specific ThriveS
  • Formulated to be safe for shrimp
  • Convenient pump top
  • Can be used up to 3 times per week
  • Flourish Tabs Growth Supplement Flourish Tabs Growth Supplement
  • Available in 10 tab and 40-tab packs
  • Less messy than liquid fertilizers
  • Should not alter water parameters
  • API ROOT TABS Freshwater Aquarium Plant Fertilizer API ROOT TABS Freshwater Aquarium Plant Fertilizer
  • Invertebrate safe
  • Available in 10-tab packs
  • Less messy than liquid fertilizers
  • The 6 Best Aquarium Plant Fertilizers – Reviews 2021

    1. Flourish Freshwater Plant Supplement– Best Overall1Seachem Flourish Freshwater Plant Supplement

     

    The Flourish Freshwater Plant Supplement is the best overall aquarium plant fertilizer because of the quality of this product. This supplement is made by Seachem, which is a trusted name in the aquatics community. This product is available in 5 sizes from 50-1000ml.

    This plant fertilizer includes necessary minerals, nutrients, and phytohormones to bring out the best growth in your aquarium plants. Phytohormones are important for regulating plant growth, activation of shoots, stress response, and root growth. This fertilizer may help improve disease resistance and mineral absorption in your plants. Some people have even found this fertilizer to work well for terrestrial plants as well. This product does contain copper, which is usually not safe for invertebrates like snails and dwarf shrimp, but if this product is not overdosed, it can be safe for invertebrates because of its low percentage of copper.

    This fertilizer does have iron in it, which means it may oxidize with exposure to air. This fertilizer is clear, but with oxidization it will turn grey or black and may stain fabric or wood, so make sure to keep it somewhere safe where it won’t get spilled.

    Pros
    • Available in 5 bottle sizes from 50-1000ml
    • Includes necessary minerals and nutrients for plants
    • Includes phytohormones to improve growth
    • May improve disease resistance and mineral absorption with continued use
    • May work well for terrestrial plants
    • Can be safe for invertebrates if dosed appropriately
    Cons
    • Can stain items with oxidization
    • Not safe for invertebrates if overdosed

    2. API Leaf Zone Freshwater Aquarium Plant Fertilizer– Best Value2API Leaf Zone Freshwater Aquarium Plant Fertilizer

     

    The best aquarium plant fertilizer for the money is the API Leaf Zone Freshwater Aquarium Plant Fertilizer. This product is cost-effective and available in 8oz and 16oz bottles. It has a measuring cup built into the cap that is easy to read and use.

    This plant fertilizer uses iron and potassium to boost the growth of your plants. Iron will help prevent yellowed leaves in your plants and potassium will boost photosynthesis, improving color and growth. This product does not include copper and is safe for shrimp, snails, and over invertebrates. The measuring cup built into the lid makes measurements for almost any tank size easy and helps prevent overdosing the product.

    The iron in this product means it is subject to oxidization and may stain items if allowed to oxidize on them. This plant fertilizer does not include phytohormones or active nutrients or minerals other than chelated iron and potassium.

    Pros
    • Available in 8oz and 16oz bottles
    • Measuring cup built into the cap
    • Contains iron to prevent yellowing of leaves
    • Contains potassium to boost colors and growth
    • Invertebrate safe
    Cons
    • Can stain items with oxidization
    • Only includes two active nutrients

    3. NilocG Aquatics Aquarium Fertilizer Shrimp Specific ThriveS– Premium Choice1Seachem Flourish Freshwater Plant Supplement

     

    The premium choice for aquarium plant fertilizers is the NilocG Aquatics Aquarium Fertilizer Shrimp Specific ThriveS. NilocG has multiple products in their Thrive line but ThriveS is specifically formulated for use in shrimp tanks. This product is available in 500ml, 2000ml, and 4000ml sizes. One 500ml bottle can treat 2500 gallons of water.

    This fertilizer features a convenient pump top, allowing you to dose based on the number of pumps instead of using messy measuring cups. This product contains necessary nutrients like nitrogen, phosphate, magnesium, iron, and calcium. It does not contain copper and is made to be safe for shrimp and other invertebrates. It can be used up to 3 times per week and will help boost the growth of the plants in your shrimp tank, improving shrimp health and reproduction.

    This plant fertilizer does contain iron, so it may stain items with oxidization. If you’re using this for a tank smaller than 5 gallons, then you may need to use a syringe for dosing since one pump of this fertilizer is enough for a 5-gallon tank.

    Pros
    • Formulated to be safe for shrimp
    • Available in 3 sizes from 500-4000ml
    • Convenient pump top
    • Includes necessary minerals and nutrients for plant growth
    • Can be used up to 3 times per week
    Cons
    • Can stain items with oxidization
    • Premium price
    • Difficult to dose for tanks smaller than 5 gallons

    4. Flourish Tabs Growth Supplement4Seachem Flourish Tabs Growth Supplement

     

    Flourish Tabs Growth Supplement is a great product pick for plants that require root fertilization. It can be purchased in 10- and 40-tab count packs. The ingredients in these root tabs are very similar to the Flourish liquid supplement but are more easily absorbed by root feeder plants.

    These root tabs contain essential trace elements, amino acids, vitamins, and minerals to boost growth and health of aquatic plants. These are intended to slowly release nutrients into the substrate and only need to be replaced every 3-4 months. These root tabs should not alter water parameters, but if you have very soft water, they may lower your pH slightly.

    These tabs should be placed approximately every 4-6 inches for maximum efficacy, and it’s recommended to use 6 tabs for every 10 gallons, so these may be costly every few months. These tabs do include copper, so they may not be safe for aquariums with shrimp or other invertebrates.

    Pros
    • Available in 10 tab and 40-tab packs
    • Contain necessary trace elements, proteins, and nutrients for growth
    • Slowly release into the substrate over multiple months
    • Should not alter water parameters
    • Less messy than liquid fertilizers
    Cons
    • Should be replaced every 3-4 months
    • Manufacturer recommends 6 tabs for every 10 gallons
    • Contain copper so may not be safe for shrimp

    5. API ROOT TABS Freshwater Aquarium Plant Fertilizer5API ROOT TABS Freshwater Aquarium Plant Fertilizer

     

    The API ROOT TABS Freshwater Aquarium Plant Fertilizer are a good option for plants that absorb nutrients via the roots. These are only available in one pack size with 10 tabs.

    These root tabs contain essential nutrients for plants to flourish, including carbon, potassium, and iron. These tabs do not contain copper, so they are safe for most invertebrates. These are less messy than liquid fertilizers and even though they contain iron, there is little risk of oxidization stains. These can be placed directly into the substrate and covered with newly planted plants to help them start off strong in your tank.

    It is recommended to replace these root tabs monthly for maximum efficacy. These should be placed approximately every 30 square inches, or 6 tabs per 10 gallons. These tabs may be difficult to place without causing water cloudiness.

    Pros
    • Slowly release into the substrate over a month
    • Contain essential nutrients for plant growth
    • Invertebrate safe
    • Available in 10-tab packs
    • Less messy than liquid fertilizers
    Cons
    • Should be replaced monthly
    • Manufacturer recommends 6 tabs for every 10 gallons
    • May be difficult to place without clouding the water

    6. Winchester Gardens Highland Rim Aquatic Fertilizer6Winchester Gardens 12 Count Highland Rim Aquatic Fertilizer Bag

     

    The Winchester Gardens Highland Rim Aquatic Fertilizer are a great root tab option for ponds. These are specially formulated for water lilies and lotuses but can be used for other large aquatic plants as well. There are 12 root tabs in a package.

    These root tabs are formulated with nitrogen, phosphorus, and potassium. They will help boost growth in your pond plants and may help improve disease resistance. These tabs are not formulated with copper, so they are intended to be safe for all aquatic life. These are made to not break apart when wet and should not cloud your water.

    These tabs should be replaced every 2 months throughout the spring and summer. One of the main ingredients in these root tabs is phosphorus, which can enter local waterways via runoff, causing problems with water quality. Phosphorus-containing fertilizers are illegal to purchase in some states, so it’s important to check this prior to purchase. These are not a great option for aquarium plants but will help improve growth in pond plants.

    Pros
    • 12 tabs per package
    • Formulated to be safe for all aquatic life
    • Will boost growth in pond plants like lotuses and water lilies
    • Will not break apart or cloud water
    • May help improve disease resistance in plants
    Cons
    • Should be replaced every 2 months
    • Phosphorus may decrease local water quality
    • Phosphorus-containing fertilizers are illegal in some areas
    • Not ideal for aquarium plants
    • Only available in one package size

    Buyer’s Guide

    Types of Aquarium Fertilizers:
    • Liquid

    For plants that can pull nutrients from the water column, liquid aquarium plant fertilizers are a great option. They are dosed directly into the water and will disperse throughout the aquarium, providing nutrition to plants throughout the tank. Liquid fertilizers may come with a pump top that allows for easy dosing, or they may come with a cap that has measuring marks in it to allow for easy dosing. This type of fertilizer is effective but can be messy. Usually, liquid fertilizers should be used 1-3 times per week.

    • Root Tabs

    Some plants are unable to pull nutrients from the water column and require nutrient-rich substrate. Root tabs are an excellent way to improve the nutrient levels within your aquarium’s substrate. These pre-formed tabs are pressed directly into the substrate and covered over with plants or substrate. They do not require frequent replacement, usually only needing to be replaced every month or more. Root tabs will not be an effective form of fertilization for plants that cannot absorb enough nutrients via their roots or plants that float and do not contact the substrate.

    • Substrate

    As more and more people have begun keeping planted tanks, manufacturers have started developing aquarium substrates that are rich in the nutrients that many plants need to thrive. These substrates are often more expensive than other types of substrates, like gravel and sand. Over time, plants may pull most of the nutrients out of the substrate, which will require supplementation or replacement of the substrate. It’s important to check the ingredients in these substrates to ensure they are safe for all aquatic life if you intend to keep any type of invertebrates.

    Things to Consider When Choosing an Aquarium Plant Fertilizer for Your Aquarium:
    • Your Plants: Different plants have different needs when it comes to nutrient absorption. Plants like Vallisneria, Anubias, Ludwigia, and Crypts require nutrient-rich substrate. There are plant-specific substrates you can purchase for plants like these, but those substrates are not ideal for all tanks or preferences. Root tabs are a great way to acquire enough nutrients within your aquarium’s substrate for root feeder plants. Plants like Java moss, Hornwort, Red Root Floaters, Water Lettuce, and Cabomba absorb all or most of their nutrients from the water column itself. For water column feeders, liquid fertilizers you add directly to the water are the perfect way for these plants to receive enough nutrients.
    • Your Invertebrates: Shrimp are extremely sensitive to copper, but so are other invertebrates like crabs, snails, and crayfish. Some fertilizers that contain copper are considered safe for use with invertebrates as long as they are dosed correctly but overdosing these can be deadly to your invertebrates. If you are not comfortable taking the chance, then copper-free fertilizers are the best option for your aquarium. If you don’t have any invertebrates in your aquarium, then copper is not generally a problem. This gives you a broader selection of fertilizers to choose from.
    • Your Tank: Freshwater and saltwater plants have different nutrient needs. Not all aquarium plant fertilizers are safe or approved for use in both freshwater and saltwater tanks. Identifying if the fertilizer you are considering purchasing is safe to be used in your type of tank, whether freshwater or saltwater, will save you time and money in the long run.
    • Your Setup: Aquarium plants and pond plants can have different nutrient needs. Some plants can be used in ponds and indoor aquarium setups, like some varieties of water lilies, hornwort, and water lettuce, and will have similar needs regardless of where they are kept. Other plants are more sensitive to changes in water parameters, sunlight, or temperatures, like Crypts, Glossostigma, Riccia, and Rotala. These plants are best kept in indoor tank setups where all parameters can be closely monitored and kept in range. These plants will have different needs from plants that are kept in outdoor environments where they may receive nutrients from rainwater, aquarium life like insects, fish, and amphibians, and runoff from other bodies of water.
    • Your Local Laws: Many fertilizers contain phosphorus, but phosphorus-containing fertilizers are illegal to purchase in some areas due to the dangers they pose to native waterways. If you are planning on purchasing a phosphorus-containing fertilizer, make sure to check your local laws before you purchase. This is especially important if you intend to use the fertilizer outdoors in water gardens or ponds. If there is any chance of flooding, overflow, or runoff, then phosphorus-containing fertilizers are not recommended.

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    Conclusion

    Aquarium plant fertilizers are an easy way to boost the health, growth, and color of your aquarium plants. These reviews of the 6 best aquarium plant fertilizers will help you narrow your search for the perfect plant fertilizer for your aquarium’s needs. You may need to use root tabs and liquid fertilizers in your tank, depending on your plants.

    The best overall pick for aquarium plant fertilizers is the Flourish Freshwater Plant Supplement because of its high level of efficacy and safety. For a more premium product, the NilocG Aquatics Aquarium Fertilizer Shrimp Specific ThriveS is a highly effective option that is safe for invertebrates like shrimp and snails. The best value product is the API Leaf Zone Freshwater Aquarium Plant Fertilizer because it’s effective but also cost-effective.

    Adding an aquarium plant fertilizer to your tank will boost the growth of your plants, causing people to wonder what you’re doing to achieve such fantastic results in your tank. Fertilizers are so easy to use that anyone can do it. You can leave people wondering what you’re doing to produce such beautiful plants, or you can share your secrets with your friends, helping them achieve beautiful aquarium plants as well.


    Featured image credit: Lamiot, Wikimedia Commons