Which Planted Tank Fertilizer Is Right for You?

Ever wonder how professionals and even advanced hobbyists make those gorgeous aquascapes bursting with plant life? The three key ingredients that make aquatic plants happy are:

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

Many beginners will ignore that last piece of the puzzle because the world of fertilizers seems like a complicated hot mess. Although dry fertilizers seem to be the most popular choice because they are cost-effective and can be customized, many people don’t mention the steep learning curve or how chemical balances can easily get out of line if they don’t understand what they are doing.

Aquatic Plants really need fertilizers?

If you want your plants to really thrive and not just survive, the simple answer is yes. 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 can be nutrients that plants only require in small quantities, such as iron and boron.

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 Central)

To avoid these problems, hobbyists use fertilizers to make sure their plants always have access to all the nutrients they’ll need. Let’s take a look below at the most common and readily available fertilizers for your average tank.

The Easy Option: Aquarium Co-Op Easy Green

You might be thinking “Uh, I just purchased my first few plants.” I have no idea if they’re doing well, much less what nutrients they might be missing. Where’s the easy button?” That’s where Aquarium Co-Op’s Easy Green all-in-one fertilizer comes in. We originally developed it for our own in-store use because we wanted something that was:

1. Simple to use without the need to measure out hundreds of different supplements. This product is much more potent and has a higher nutrient content than other products on the market. Reasonably priced because a little bit goes a long ways

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. 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. 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. That’s all there is to it.

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 for every 10 gallons water once per week for low- to medium-light tanks; and double for high-light tanks.

One bottle of this product will last approximately one year for a 55 gallon tank. 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

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 really high bioloads

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

Ingredients: has 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. 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

This is a very diluted product, so you will go through the bottle quickly.

The bottom line: While it won’t give you super-growth, it’s better than nothing.

Seachem Flourish Series – Mix-and-Match

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 you be able to customize your nutrients to meet your needs. This means that their fertilizers may not be suitable for beginners.

Ingredients: totally depends Most novices should start with Flourish Comprehensive, which contains most of the elements and minerals you’ll need for low-light plants. 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: $10 to $70 or more

Flourish Comprehensive is $10.50 and Flourish Trace is about $10.50 per 16.9 oz bottles. They are low in nitrogen and phosphorus, just like API Leaf Zone. 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 dependent

Not only is it a hassle to deal with multiple bottles, but each of them have very different measurement amounts and treatment frequencies. 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. Because everyone is different, there is no “best product”. 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!