Which Planted Tank Fertilizer is Right for You?


Which plant-based fertilizer is best for you?

Wondering how professional hobbyists and advanced hobbyists create stunning aquascapes that are bursting with plant life? It all boils down to three things that make aquatic plants happy.

– Use good lighting. – Add nutrients as necessary.

Many beginners will ignore that last piece of the puzzle because the world of fertilizers seems like a complicated hot mess. While dry fertilizers are highly affordable and customizable, everyone on the internet recommends them. However, they neglect to mention the steep learning curve and how easy it is for chemical balances to get out of control if you don’t know what you’re doing.

Aquatic Plants Actually Need Fertilizers

You want your plants not to survive but thrive. Just as humans require certain nutrients to live, plants must have fundamental building blocks to grow:

– Macronutrients are nutrients that plants consume in large quantities, such as nitrogen, phosphorous, and potassium. – Micronutrients are nutrients that plants need in trace amounts, such as iron, boron, and manganese.

Plants will grow differently if any of these substances are lacking. Check out this plant deficiency diagram that shows what happens when certain elements or minerals are missing:

Source: Aquatic Plant Central

These problems can be avoided by hobbyists who use fertilizers to ensure that their plants receive all the nutrients they require. So let’s take a look at some of the most popular, readily available fertilizers that will work for your average planted tank.

The Easy Option: Aquarium Co-Op Easy Green

You might be thinking “Uh, I just purchased my first few plants.” I don’t know if they are doing well or what nutrients they may be lacking. Where’s the easy button?” That’s where Aquarium Co-Op’s Easy Green all-in-one fertilizer comes in. It was originally designed for our in-store use, but we needed something more.

1. Easy to use, without having to measure out a ton of different supplements 2. This product is much more potent and has a higher nutrient content than other products on the market. Because a little goes far, it is reasonably priced

Easy Green all-in-one liquid fertilizer

Intended For: aquariums that are at least moderately stocked with plants

Easy Green contains healthy amounts of all three macronutrients to get great growth, so it’s not intended for tanks with very high bioloads and only one plant. If you have an aquarium with normal bioloads and a bunch of plants that you want to look nice, this is the fertilizer for you. And yup, it’s fish and invertebrate safe.

Note: “High bioload” generally refers to aquariums with lots of animals, poop, and excess food floating around. A high level of organic matter in the water can lead to nitrogen and phosphorus that plants can eat. High bioloads can cause toxic ammonia if they are not properly managed.

Ingredients All three macronutrients (nitrogen and phosphorus) as well as the top six micronutrients are in greater concentrations to maximize effectiveness

Cost: $15 for 8 oz bottle

Easy Green is an all-in one fertilizer which covers most of your needs for plants. Easy Green is now available in Canada via Amazon.com. If you have lots of red plants, you can dose extra iron with Easy Iron. If you need help fighting algae, consider adding Easy Carbon. There are no other bottles you need.

Easy Root Tabs can be used to attach to gravel, sand or any other inert substrate if you have plants that prefer to eat from their roots than the water column.

Easy Fertilizer Package

Directions: 1 pump per 10 gallons of water once a week for low to medium light tanks (and double the dose for medium to high light tanks)

For a 55 gallon low light tank, that means one bottle will last you about a year. If your aquarium has medium to high light, then dose two to three times a week. Use test strips to measure the water in your aquarium and aim for 50ppm of Nitrates. It’s as simple as that.

The bottom line: Easy Green is easy to use and great for making green leaves. Easy Green is a great choice for beginners looking for a bulletproof, comprehensive fertilizer.

The Cheap Option: API Leaf Zone

If you go to your local pet store and find their selection of liquid fertilizers, most likely API Leaf Zone will be one of the options. It’s cheapest bottle on the shelf and should do the trick, right?

API Leaf Zone

Designed for: low tech planted tanks with high bioloads

Translation: your plants are fairly low maintenance and are currently living off fish waste and flakes in the tank.

Ingredients only contains potassium and iron

API assumes that your tank has high bioload and contains a lot of nitrogen, phosphorus and potassium. Leaf Zone also provides potassium. Because it aids with leaf growth, it also adds iron. But… what about all the micronutrients?

Cost: $6.50 for 8 oz bottle

You can’t beat the price but you get what your pay for.

Directions: 5 mL per 10 gallons per week

That’s pretty diluted, so you’re going to run through the bottle pretty quickly.

Bottom Line: It won’t provide super growth for your plants, but it’s better than nothing.

The Mix-and-Match Option: Seachem Flourish Series

Seachem Flourish fertilizer line

Intended for: Any planted tank

The reason why Seachem has so many supplements is because everyone’s planted tank is unique – different bioloads, water hardness, low vs. high light, and so on. Seachem wants to give you the freedom to adjust the nutrients to suit your needs. Their fertilizers are not necessarily for beginners.

Ingredients it all depends. The majority of novices should start off with Flourish Comprehensive. It contains most elements and minerals that low-light plants need. Seachem then recommends adding Flourish Trace on separate days to ensure you have an ample amount of micronutrients. Seachem offers a way to purchase individual building blocks if you still experience plant deficiencies.

Cost: $10 to $70 or more

Flourish Comprehensive is $10.50 and Flourish Trace is about $10.50 per 16.9 oz bottles. However, like API Leaf Zone, they’re very low on the two of the main macronutrients – nitrogen and phosphorus – just in case you have a high bioload tank. Flourish Nitrogen can be purchased for $10.50 and Flourish Phosphorus is available for $10.50. You could end up buying seven bottles.

Directions: totally depends

It is not only a hassle to have multiple bottles but also each bottle has different treatment frequencies and measurement amounts. Some bottles say “5ml per 60gallons per week”, while others say “2.5ml/40gallons twice a weekly but add more as needed.” In order to prevent novices from overdosing on fertilizer, the recommended nutrient levels are quite low.

Summary: Flourish Comprehensive provides a lot of the essential nutrients required for growing plants. However, you should be prepared to purchase additional supplements and spend some time fine-tuning how much and when to use them.

For more details on the Seachem Flourish series, check out our video on How to Use Aquarium Fertilizers.

Final Tips on Aquatic Plant Fertilizers

No matter what nutrient sources you use (e.g., fish poop, root tabs, liquid or dry fertilizers, potting soil, CO2 injection), most likely they will help. There is no single “best product” on the market because everyone’s individual setups and preferences are so different. You need to do your research and make the right decision for yourself. Also, don’t forget to learn from your mistakes. Your aquarium is a living ecosystem that is constantly changing – water, number of fish, plant size – so have fun seeing nature in action and earning your aquatic green thumb!