Seachem Flourish Review

Seachem Flourish Aquarium Fertilizer Review

The following Seachem Flourish review is designed to inform potential buyers of the pros, cons, general features and overall quality of Flourish. Seachem Flourish Aquarium Fertilizer is a freshwater aquarium fertilizer that contains many of the micro-nutrients necessary to keep one’s aquarium growing bountifully.

While it is designed to be used in conjunction with macro-nutrient supplements, Seachem Flourish Aquarium Fertilizer is an extremely effective micro-nutrient fertilizer and overall gets a high quality rating.


  • Great all-around fertilizer for micro-nutrients
  • Does not affect tank chemistry
  • Does no harm to fish
  • Increases vitality of plants


  • Caps on bottles are at times notably loose
  • High doses can be tolerated with varying success depending on the tank

Seachem Flourish is a liquid aquarium fertilizer which focuses on micro-nutrients that help the liveliness and growth of aquatic plants in an aquarium. Compared to Seachem’s other three liquid fertilizers, Flourish Nitrogen, Flourish Phosphorus, and Flourish Potassium, Seachem Flourish is the most comprehensive fertilizer.

While the other Seachem liquid fertilizers are used to provide macro-nutrients, Flourish provides a myriad of micro-nutrients that are essential for plant development and it does not do harm to fish or invertebrates such as shrimp.

Packaging and Sizing

Seachem Flourish comes in multiple sizes, ranging from 50 mL up to 4L. Flourish liquid aquarium fertilizer comes packaged in a sleek, cylindrical tube with a small white cap on the top. The packaging serves a functionality as well, as the cap can be used as a measuring device, aiding inputting the correct dosage into one’s aquarium.

Seachem Flourish Dosing

It is recommended by Seachem to put one capful (approximately five mL) into a 250L tank once or twice a week. Smaller dosages can also be measured out from the cap, as it has small dividing lines on its interior, each indicating approximately one mL. From functionality and aesthetic point of view, the package of Flourish is just what one would want it to be.


Flourish prides itself as being a comprehensive micro-nutrient aquatic fertilizer, and it certainly is. Seachem guarantees their analysis of each bottle of Flourish to contain the following percentages of each nutrient:

  • Nitrogen (N) 0.007%
  • Phosphate (P2O5) 0.01%
  • Soluble Potash (K2O) 0.37%
  • Calcium (Ca) 0.14%
  • Magnesium (Mg) 0.11%
  • Sulfur (S) 0.2773%
  • Boron (B) 0.009%
  • Chlorine (Cl) 1.15%
  • Cobalt (Co) 0.0004%
  • Copper (Cu) 0.0001%
  • Iron (Fe) 0.32%
  • Manganese (Mn) 0.0118%
  • Molybdenum (Mo) 0.0009%
  • Sodium (Na) 0.13%
  • Zinc (Zn) 0.0007%

With so many different micro-nutrients, Flourish assures that its bases are covered to help any type of aquatic plant grow even more voluptuously.

It may be of concern to some potential buyers that the product contains copper, which is notably harmful to invertebrates like shrimp. However, with such a minuscule amount of copper, Flourish remains harmless to invertebrates. It may also be potentially concerning that Flourish contains phosphate, which is known to cause algae growth in aquariums. However, again with such a tiny amount present in Flourish’s overall composition, one would have to use 1,000 times the recommended dose to actually promote any kind of algae growth.

Finally, even with all these chemicals and nutrients, Seachem Flourish does not affect the pH balance of aquariums when used as directed, which is important to those aquarium owners who have pH-sensitive plants or living fish in their tanks.

Ease of Use

When discussing ease of use, it really doesn’t get much more simple than using Flourish. With only one to two doses maximum required per week and a cap that also serves as a measuring cup, Flourish is quite simply one of the easiest to use liquid aquatic fertilizers available.

This makes Flourish a great choice for beginning aquarium keepers and advanced enthusiasts alike, and with stellar results, it’s hard to argue that a more complex route of fertilization would be necessary.

How Does Seachem Flourish Compare vs The Competition

With all these features, let’s now see how Flourish compares to its other micronutrient liquid fertilizer competitors on the market.

Seachem Flourish vs NilocG Aquatics Thrive+ All in One Liquid Fertilizer

NilocG Aquatics Thrive+ All in One Liquid Fertilizer is truly an all in one fertilizer, containing both macro-nutrients and micro-nutrients. With a packaging that has a pump on the top, NilocG Aquatics Thrive+ All in One Liquid Fertilizer simplifies the process of distributing fertilizer to the aquarium, allowing users to simply pump once and be done with the endeavor. This may be more simple than the capful method offered by Flourish but actually acts as more of an inhibitor than anything.

With the pump method, one can only get a set amount of fertilizer into the tank, with Flourish’s cap method, smaller or larger doses can be distributed to the tank as needed. In addition NilocG Aquatics Thrive+ All in One Liquid Fertilizer has micro-nutrients and macro-nutrients which makes it good for beginners who are looking for an all in one liquid fertilizer, but for those with more sensitive or complex aquariums, Flourish’s micro-nutrient only concoction allows flexibility for each tank and allows the user to decide how much of each macro-nutrient is right for their specific tank.

Seachem Flourish vs Glosso Factory All in one Planted Aquarium Fertilizer

Glosso Factory All in one Planted Aquarium Fertilizer is another micro/macro combination fertilizer with a pump top. For the same reasons as NilocG Aquatics Thrive+ All in One Liquid Fertilizer, it compares almost identically to Flourish.

Seachem Flourish vs CrystalClear Winston CC01760 60 Tablet Thrive Aquatic Plant Fertilizer

This aquatic fertilizer comes in tablet form, making dosage supremely easy compared to the liquid-based nature of Flourish. CrystalClear Winston CC01760 60 Tablet Thrive Aquatic Plant Fertilizer is used as an all-around aquatic plant fertilizer with a blend of micro and macro-nutrients, making it a great choice for novice aquarium keepers. With the increased flexibility that Flourish offers, however, it is a much more logical choice for more experienced users as well as novices.


Overall, this Seachem Flourish review rates Flourish at an impressive 4.5/5 stars, seeing as it stands shoulder to shoulder with its competitors and can be used by beginners and advanced aquarium keepers alike.

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