Which plant-based fertilizer is best for you?

Wondering how professional hobbyists and advanced hobbyists create stunning aquascapes that are bursting with plant life? The three key ingredients that make aquatic plants happy are:

– Good lighting – Substrate as needed – Nutrients, like fertilizers

This last piece is often overlooked by beginners because fertilizers seem like a complex and confusing world. 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 really need fertilizers?

If you want your plants to really thrive and not just survive, the simple answer is yes. The building blocks that plants need to grow are just as important as the nutrients they require to survive.

– Macronutrients refer to nutrients that plants consume large amounts of, such as nitrogen and phosphorous. – Micronutrients can be nutrients that plants only require in small quantities, such as iron and boron.

If any one of these compounds is lacking, plants start growing differently or not at all. Check out this plant deficiency diagram that shows what happens when certain elements or minerals are missing:

(Source: Aquatic 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 may be thinking, “Uh-oh, I just bought my very first 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. It is higher in nutrients and more potent than the ones on the market. Reasonably priced, because a little goes a long way

Easy Green all-in-one liquid fertilizer

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

Easy Green has healthy levels of all three macronutrients for great growth. It is not recommended for tanks with high bioloads or 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. Having high levels of organics in the water produces nitrogen and phosphorus, which plants can consume. If not managed well, high bioloads may also cause high levels of ammonia which can be toxic to animals.

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 that covers all your bases for the majority of plants, so if you’re only going to buy one fertilizer, get this one. Easy Green can also be purchased through Amazon.com Canada. Easy Iron can be used to boost iron levels in those with lots of red plants. If you need help fighting algae, consider adding Easy Carbon. There are no other bottles you need.

If you have plants that prefer to feed from their roots rather than the water column (such as Cryptocoryne, sword plants, and bulb plants), then get a pack of Easy Root Tabs to stick into your gravel, sand, or other inert substrate.

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)

A 55 gallon low-light tank will require one bottle to last for 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 that simple.

The bottom line: Easy Green is easy to use and great for making green leaves. If you’re a beginner looking for a comprehensive, bulletproof fertilizer or you’re not getting the results you want, Easy Green may be just the thing you need.

API Leaf Zone: The Best Option

API Leaf Zone is likely to be among the liquid fertilizers available at your local pet shop. The cheapest bottle should be enough.

API Leaf Zone

Intended for: Low-tech, planted tanks with very high bioloads

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

Ingredients: contains only 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. It also includes iron to aid in new leaf growth. 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.

Seachem Flourish Series – Mix-and-Match

Seachem Flourish fertilizer line

Designed for: any plant 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 you to have the ability to completely customize the nutrients to fit your specific requirements… which means their fertilizers aren’t necessarily beginner-friendly.

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 suggests that you use Flourish Trace on separate day to ensure that you get sufficient micronutrients. If you’re still seeing plant deficiencies, Seachem has separated out key nutrients into different products so that you can individually buy the building blocks you require.

Cost: $0 to $70 or More

Flourish Comprehensive and Flourish Trace are about $10.50 each for a 16.9 oz bottle. They are low in nitrogen and phosphorus, just like API Leaf Zone. If you don’t, then you can spend another $10.50 on Flourish Nitrogen and another $10.50 on Flourish Phosphorus… by the time you’re done adding all the necessary nutrients, you may be buying a lineup of seven bottles or more.

Directions completely depends

Not only are multiple bottles cumbersome to manage, but each one has very different amounts and treatment times. It may say “5 ml for 60 gallons per Week” or “2.5 ml for 40 gallons twice per week, but add more if necessary.” The nutrient concentrations are low enough to prevent beginners from overdosing. Therefore, you will need more fertilizer than what the bottle suggests.

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!