Flourish Excel vs API CO2 Booster

Flourish Excel vs API CO2 Booster: Choose the Best!

Owning a planted aquarium isn’t a piece of cake. Along with our fish pals, we need to take care of the plant buddies too. Hence, we gotta choose the best fertilizer or boosters for them which is indeed an intricate process.

So, which one would you choose if it’s Flourish Excel vs API CO2 Booster?

Flourish Excel seems to be more effective than API CO2 Booster. However, Excel doesn’t contain CO2 directly like API. Nonetheless, API is a versatile product and can be used in all kinds of fisk tanks. On the other hand, Excel is not suitable for some plants like moss, fern, val, etc.

Are you still scratching your head? We got you! Sit relaxed and keep walking with us through the whole writing. In the end, you’ll have your winner in hand.

Is Flourish Excel And API CO2 Booster the Same?

Source: https://www.aquariumcoop.com/

Well yes, Flourish Excel and API CO2 are quite similar.

Flourish Excel is a bioavailable organic carbon supply. It’s made for the planted aquarium that promotes aquatic plant development. It was designed to make plant care easier without the use of carbon dioxide infusion. However, it’s not a replacement for CO2 entirely. 

It provides plants with the necessary molecules required for photosynthesis. It retains iron in a reduced condition so that it can be easily absorbed by plants.

On the other end, API CO2 Booster is a liquid carbon source that can be used instead of carbon injection. In freshwater aquariums, it increases plant growth. It provides needed carbon in a form that plants can take from water. It can be used alone or in tandem with a CO2 system while not influencing the pH levels.

So, is Flourish Excel and API is okay for fish and plants?

Flourish Excel is completely harmless for freshwater fish but can be harmful to saltwater fish. If you have water weeds in your aquarium, then use Excel every other day.

Keep in mind, overdosing can kill your fish and melt your dwarf hairgrass.

However, Flourish Excel does not contain any minerals that may have possible effects on the water. As a result, when used as directed, it has no effect on pH, GH, or KH.

Quite similarly API CO2 Booster is not harmful to freshwater and good for saltwater fish as well. It provides carbon to aquatic plants while having little effect on fish. It does possess antibacterial properties. It’s also suitable for shrimp and snails.

Want to know the best thing about using API CO2 Booster? The chemical changes in the water are too inadequate to alter the aquatic environment like Excel.

However, does Flourish Excel have antibacterial properties like API CO2 Booster?

Antibacterial properties are present in Flourish Excel as well. But it can cause problems while cycling. It also has Glutaraldehyde, which is an algae remover. It is the main component of Flourish Excel and, if applied, can harm certain plants like moss, fern, Vallisneria, etc. If you overdose Flourish Excel, it can and will harm algae and plants. Moreover, Flourish Excel, when applied in big quantities, can kill fish too.

So, Excel and API are quite similar when it comes to properties or shelf life. But they vary in terms of application and effectiveness.

Now let’s take a look at the quick comparison between Flourish Excel and API Co2 Booster.

Quick Comparison

Wondering how Flourish Excel and API CO2 Booster can help your aquatic plants? Have questions about the Flourish Excel and API CO2 Booster? We’ve analyzed both Excel and Booster in detail for your ease.

But before diving into the thorough discussion let’s look at the following table.

You can also look at the following chart to have an initial comparative idea.

Don’t worry! We’re not pulling the curtain down already. This show still has a lot to offer you. So, keep yourself engaged with us to know which fertilizer get the upper hand in the end.

Application Schedule

The application schedule for Flourish Excel and API CO2 Booster is pretty effortless.

Both Flourish Excel and API should be applied daily. However, you can pour Excel straight on top of your aquatic plants. The dose should be about 5 ml for every 53 gallons of water. You can dose 5ml of excel to 11 gallons of water after water changes.

On the other hand, API CO2 Booster needs to be applied after taking into account tank size and water volume. This is done in order to avoid an overdose of liquid CO2 Booster. You’ll need to apply 1 ml of API CO2 Booster for every 10 gallons of water.

Application schedule for Flourish Excel daily dosage:

Water Volume (Gallons)Daily Dose (ml)
Recommended Dose Ratio505
Spec V Aquarium5.600.53
Spec III Aquarium3.500.09

Application Schedule for API CO2 Booster daily dosage:

Water Volume (Gallons)Daily Dose (ml)
Recommended Dose Ratio101
ADA 60p171.7

Well, you can use pipette or syringe to get the accurate dosage. That’s why we’ve brought some of the precise and authentic pipette recommendations into our list. Take a look!

Winner: Tie

Cost of Application Per Gallon

When it comes to the cost of application of your products you need to observe if its actually justifying the expenditure. Therefore, we’re going to evaluate the cost per year of the Excel and API side by side.

A table has been created which will show the cost of application for Flourish Excel:

Annual Quantity (ml)Cost Per Year (USD)
Dose per gallon 52$1.15
ADA 60p (17 Gallons)920$19.62
Tetra 55 Gallons2977$63.47

A table has been created which will show the cost of application for API CO2 Booster:

Annual Quantity (ml)Cost Per Year (USD)
Dose per gallon36.5$1.3
10 Gallons365$13
ADA 60p (17 Gallons)620.5$22

As you can see, the annual cost of API is moderately less than Excel. But the question is, are users noticing enough change in their plant health using API? The answer is no!

According to aquarists Excel dosage effectiveness is more noticeable than API. That’s why I think Excel will generate the value for money here rather than API.

Winner: Flourish Excel


Source: https://whyledlight.com/

To keep plant development balanced, three things must always be in sync. These are light, nutrients, and CO2. Maintaining all the mentioned things and applying excel will lead to better growth. 

When it comes to nutrients and CO2, you must observe the tank carefully. If you notice algae starting to appear, consider it an alarm bell. This indicates an imbalance in nutrients and you may have to increase CO2 to fix it. However, creating a balance in your planted tank lighting is a bit more complex.  But creating a balance with lights will require due diligence on the part of the aquarist. 

Are you thinking about updating your fish tank’s entire lighting system? Here are a few lighting systems that we recommend:

Now let’s check the compatibility of Flourish Excel and API CO2 Booster with your aquarium.

Water Type

Flourish Excel can be used safely on freshwater fish. Whereas, API CO2 Booster is non-toxic to both freshwater and saltwater fish. 

The thing is, Flourish Excel should not be applied if the fish tank contains saltwater fish. It’s important to know the exact volume of water when dosing Flourish Excel. It’s critical, especially for smaller tanks like Tetra ColorFusion Aquarium. The ecosystem of small tanks is quite vulnerable. Therefore, even a minuscule fraction of Flourish Excel can make a big difference in the tank. 

API CO2 Booster is non-toxic to both freshwater and saltwater fish. You can have shrimp and craw crabs without worrying of them being poisoned. The amount of water in fish tanks will also play a part in determining how much of it is used.

Winner: API

Aquarium Installation and Light

A stunning aquatic plant architecture requires proper light and CO2 injection. It is critical in maintaining these ingredients in balance in order to develop a variety of aquatic plants.

We advise a single 150W metal halide light for a tank of roughly 50 gallons. Alternatively, a 150W metal halide lamp with two 36W power compact lights can be used. Almost all aquatic plants thrive in this environment. Fortunately, it won’t be too much for plants that need some shade.

For a smaller size tank of about 15 gallons, you can use two 36W PC lights. However, for a large tank like 180 gallon SC Aquariums, we would recommend three 150W metal halide lights.

Well, there is a very crucial point behind this setup discussion. We noticed that in this environment if you dose Flourish Excel accurately, it seems to work faster than API.

Winner: Flourish Excel

Issues Faced During an Overdose

When working with Flourish Excel or API CO2 Booster, it is critical to use the correct amounts. If you don’t pick the right dose of Excel, you can risk harming your plants. 

When you overdose, what plants are killed?

Flourish Excel will have an impact on Anacharis, Sags, Vals, and any liverworts such as Riccia. API CO2 Booster on the other hand would harm beneficial bacteria during an overdose. However, in this case you can use the Brightwell Aquatics Microbacter. This is helpful for rapidly re-establishing nitrification bacteria in case of an emergency.

A safe level of these two carbo injectors is under 30ppm. And in most circumstances that can be measured with a drop checker. I use the NilocG Aquatics Co2 Drop Checker. It’s very convenient and constantly gave me dependable reading in roughly 2 hours.

Winner: Tie

Suggestions for Using Liquid Carbon

These are a few pieces of advice from us which we suggest you follow when using liquid carbon.

  1. Carefully pour the liquid carbon from the bottles into a pump dispenser.
  1. Each pump should be measured; the best grade bottles dispense 1ml every pump. This allows you to dosage your normal daily quantity fast and correctly.
  1. Purchasing larger bottles of liquid carbon is a better investment than thinking tiny.
  1. Every day, apply liquid carbon at the same time. It is preferable to do so just before turning on the lights.
  1. On black brush/beard algae, liquid carbon works well. Allow the damaged regions to air dry before applying it with a little paintbrush.

Try to follow the steps as much as you can. Otherwise, you might face unwanted problems.

Child and Pet Safety

Source: https://www.psychologytoday.com/

Do you’ve concerns about Pet/Child Safety regarding Flourish Excel/API CO2 Booster? Well, it’s understandable. But, should you be concerned about your child drinking Flourish Excel?

Yes, you should be concerned about Excel and Booster being a risk to children and pets. Since nothing is more important than the safety of your children and household pets. Flourish excel contains chemicals that may be hazardous to a child’s health. If a youngster consumes Excel or Booster, they should be transported to the emergency room right away.

Pets are also at risk because their bodies may react negatively to the pollutants. Although it is safe for fish, it is not necessarily safe for all creatures. Keep Excel and Booster out of reach of children by storing them in high cupboards.

Which One is Better?

If you want our opinion, we believe Excel is superior. Although API is less expensive than Flourish Excel, Excel works faster than API. However, their application process is fairly similar.


Can Flourish Excel be used to replace CO2?

A typical CO2 system cannot be replaced by Flourish Excel. Because it doesn’t contain the exact molecules the CO2 provides. However, if properly dosed, it can be very successful in growing aquarium plants. To avoid harming your fish, always follow the directions when dosing Flourish Excel.

Is CO2 Injection harmful to fish?

Most fish and shrimp can tolerate up to 30ppm CO2. However, some are more vulnerable to intoxication than others. Consider shutting off your lights and gas 24 hours before adding new fish. This will prevent the fish from being frightened by excessive gas levels.

Does Flourish Excel raise the pH of the water?

No. Flourish Excel has no buffers or minerals, thus when used as directed, it does not affect pH, GH, or KH. Flourish Excel is a carbon source for plants but not a CO2 source. As a result, it will not acidify water in the same way that CO2 will.

Can I use Flourish and Flourish Advance at the same time?

While there should be no cooperation between Flourish Advance and other products. Waiting 24 hours between doses will prevent stress caused by changing water parameters.

Bottom Line

Flourish Excel vs API CO2 Booster is a difficult comparison to make. But we have discussed both Flourish Excel and API CO2 Booster in detail. We have analyzed them and brought forward their pros and cons.

Have any questions for us regarding liquid carbon? Let us know in the comments.

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