Are aquarium plant fertilizers safe for fish? This is the question many beginners have when they start out with live aquarium plants.
And in this article, I am going to answer the question.
So are aquarium plant fertilizer safe for fish?
Yes, the plant fertilizers that are specially made to use in aquariums are totally fine for your fish as long as you don’t overdose it.
Though there are some chemical aquarium plant fertilizers that you should use only in a planted tank i.e. the tank that contains only live plants and not fish. These fertilizers are usually labeled clearly.
Are liquid fertilizers safe for fish?
Yes, liquid fertilizers that are specially made to use in a fish tank are totally safe for your fish as long as you are not overdosing it.
Liquid fertilizers contains macronutrients such as Nitrogen, Phosphorus, and Potassium. And micronutrients such as Boron, Magnesium, Iron, Copper, etc.
These nutrients are essential for plant growth.
But some of these nutrients such as nitrogen and copper can be harmful to your fish or invertebrates like shrimps in your tank if they are in large quantity in your aquarium.
That’s why you should not overdose liquid fertilizers to your aquarium plants.
For a small moderately planted tank that is less than 55 gallon, adding liquid fertilizers once a week is sufficient.
Usually, the quantity of fertilizer you should be adding in your tank varies according to the brand of the fertilizer.
And how much fertilizer you should add according to the size of the tank is given on the label of the bottle or packaging of the fertilizer.
Are root tabs safe for fish?
Just like liquid fertilizers, root tabs are safe for your fish as far as you are not overdosing it.
Root tabs contains essential micro and macro nutrients that plants require for their proper growth.
Some of these nutrients can be harmful for your fish if they are present in excess quantity in your tank such as copper and carbon.
Overdosing root tabs can result in excess amount of such nutrients.
That’s why you should always add root tabs according to the quantity mentioned on the packaging of the root tabs.
Do you really need fertilizer for your aquarium plants?
As mentioned earlier, aquarium plants require various micro and micronutrients for their proper.
Aquarium plants may get some of these nutrients in sufficient quantity such as nitrogen and carbon dioxide from the freshwater tank without any fertilizers.
But to provide all the other essential nutrients such as boron, copper, phosphorus, potassium, iron, magnesium, etc to your plants, you have to supplement it with fertilizers.
Now, every plant is different and they have different nutrient requirements.
Some plants such as red aquarium plants require a lot of nutrients and so they just can’t survive without fertilizers.
Whereas there are some hardy aquarium plants that can do well without any fertilizers.
I have written a detailed article covering all such plants (read the article)
But these plants will just survive in your tank but they will not thrive in your tank unless they get fertilizers.
So overall, it is safe to assume that almost all the aquarium plants require fertilizers to thrive and look their best in your aquarium.
Besides, if the plants don’t get sufficient nutrients then it can lead to various nutrient deficiencies.
Some common nutrient deficiencies found in aquarium plants are as follows.
- Carbon dioxide deficiency
- Nitrogen deficiency
- Iron deficiency
- Potassium deficiency
- Phosphate deficiency
- Magnesium deficiency
- Calcium deficiency
In the following image, you can see various plants deplants deficiencies and their symptoms.
(Source: Aquatic Plant Central)
How do you fertilize aquarium plants?
To fertilize your aquarium plants you need to provide them liquid fertilizers and/or fertilizers in the form of root tabs.
When to use liquid fertilizers?
You should use liquid fertilizer if you have water column feeder plants i.e. the plant that draws nutrients through their leaves from the water column.
Stem and rhizome plants such as Java moss, Java fern, Rotala Indica, Cabomba, etc comes in this category.
When to use root tabs?
You should use root tabs for root feeder aquarium plants.
These plants absorb nutrients through their roots.
And when you bury root tabs into the substrate, the nutrients from the root tabs automatically and slowly get released into the substrate.
And these nutrients are absorbed through the roots of the root feeder aquarium plants.
Now there is a lot of debate going on the internet on whether you should only feed liquid fertilizer or root tabs to your aquarium plants. Or you should feed both to your aquarium plants.
The thing is, though aquarium plants are either root feeder or water column feeder, they still get nutrients from through substrate as well as through the water column.
For example, if a plant is a root feeder aquarium plant.
Then it will get or absorb most of the nutrients through its roots from the substrate.
So, you should definitely feed it fertilizers in the form of roof tabs.
But it will also get some nutrients or absorb some nutrients through its leaves through the water column.
That’s why it is a good idea to supplement the plant with liquid fertilizer as well.
Overall, for the best results, you should supplement your aquarium plants with both root tabs as well as liquid fertilizers.
Is there any way to fertilize aquarium plants naturally?
Unfortunately, there is no way you can fertilizer your aquarium plants naturally without using any fertilizers.
Though the aquarium plants will get some nutrients such as nitrogen and carbon dioxide from your aquarium in the form of ammonia produced from fish poop in your tank.
But there is no way you can provide all the essential micro and macro nutrients that a plant required for their proper growth without adding fertilizers.
So if you don’t want your plants to just barely survive in your tank. And you want your plants to thrive and look as good as they can then you will need to supplement your plants with some fertilizers.
The quantity of fertilizer you need to feed your aquarium plants will vary according to the plant.
Some plants will require a lot of nutrients whereas others require very less amount of nutrients.
How often should I fertilize my aquarium plants?
There is no single answer I can give how often should you fertilize your aquarium plants.
Because every aquarium setup is different and so the fertilizer requirements vary from aquarium to aquarium.
Besides, which brand of fertilizer you use also comes into play when deciding how often you should fertilize your aquarium plants.
So I suggest you to start by following the doses recommended by the brand of the fertilizer that you are going to use in your aquarium.
Usually, they suggest dozing your aquarium plants on a weekly basis.
You should add the doses according to the label of the fertilizers. And give it some time of at least 2 to 4 weeks to see the results.
Then research what nutrients your plants require and in what quantity. Then test your water using a test kit.
And see which nutrients your aquarium lacks and which nutrients your aquarium contains in excess quantity.
And adjust the doses of the fertilizer accordingly.
What is the best aquarium plant fertilizer?
There are a lot of aquarium plant fertilizers available in the market.
These fertilizers have different proportions of essential nutrients and minerals.
If you are just starting out, I know it can be very intimidating to choose fertilizer for your aquarium plants.
So I highly suggest you start out with the following fertilizers because these fertilizers contain all the essential nutrients and minerals that your aquarium plants require.
Once you get some experience and as you do research about the plants in your tank, you will get better at knowing which nutrients your aquarium plant is not getting and which nutrient your aquarium plant is getting in excess quantity.
So you can mix and match different fertilizers and provide customized fertilization according to the needs of your aquarium plants.
This is one of the most recommended fertilizers to any beginner who is just starting out with live aquarium plants.
This is a liquid fertilizer so it is a very good fertilizer for water column feeder aquarium plants.
It is a tested and proven fertilizer and it will not harm any of the fish or invertebrate in your tank.
Though it does contain copper which is essential for aquarium plants but can be harmful to invertebrates like shrimps.
But the amount of copper is very low so you don’t need to worry about it as far as you are not overdosing it.
Now, this is not the best aquarium plant fertilizer you can ever provide to your live aquarium plants.
But it is a very good fertilizer if you are just starting out because it contains all the essential nutrients in low amounts that live aquarium plants require for their proper growth.
As you get some experience and do research about your plants, you will know which nutrients your plants are getting less, and then you can add that particular nutrient separately into your tank. (Seachem also has separate products that contain only specific nutrients such as iron, potassium, etc that you can supplement to your live plants if you found it necessary)
Also, using this fertilizer is very simple. You just have to pour down the amount of fertilizers as recommended on the label of the product into the cap of the bottle and simply add it in your tank.
Seachem has provided a very handy table that shows how much fertilizer you should add in your tank according to the size of your tank on Amazon. (check it out here)
Every time you add the fertilizer in your tank just make sure to tighten the bottle well and shake it well.
Seachem Flourish Tabs
If you have heavy root feeder aquarium plants in your aquarium then Seachem flourish tabs is one of the best ways to fertilize your aquarium plants.
These root tabs come with all the essential nutrients that your aquarium plant requires to thrive in your tank.
It is also harmless to fish or invertebrates in your tank.
Though it does contain copper which is harmful for invertebrates like shrimp, the amount is very very low so it will not harm the Shrimps in your tank.
Many beginners get intimidated about using root tabs in their tank because you need to bury them into the substrate of the tank.
And it seems like using liquid fertilizer is way easier than using root tabs.
But the thing is, you have to add liquid fertilizer on a weekly basis.
On the other hand, once you inserted root tabs into the substrate of your tank, you don’t need to add root tabs into the substrate for 3 to 4 months.
Because the root tabs slowly release the nutrients into the substrate overtime that the roots of your plant will absorb them.
So is Seachem flourish tabs is everything that your aquarium plants need to thrive in your tank.
No, using Seachem flourish tabs is a very good way to fertilize your aquarium plants if you have heavy root feeder aquarium plants in your tank.
But as mentioned earlier, every plant is different and they have different requirements.
Also, aquarium plants grow well when you provide them both liquid fertilizers as well as root tabs.
So as you research your plants and you get experience, you will know which nutrients your plants are not getting enough of. And so you can add such nutrients in the liquid form in your tank.
Besides, there are a couple of things you should be aware of about Seachem flourish tabs.
The first thing is, it is a bit pricey than liquid fertilizer.
But as you have to add root tabs after every 3 to 4 months, I think, it will save you time and money in the long run.
Seachem has provided a very helpful chart that shows how much root tabs you need to add according to the size of your tank on Amazon. (check it out here)
The second thing is Seachem root tabs do have some acidic properties, so your water may get slightly acidic, especially if you have very soft or unbuffered water.
Overall Seachem flourish tabs are very good fertilizers if you have root feeder aquarium plants and you are just starting out with live aquarium plants.
They are a bit pricey. But as you have to add them after every three to four months, I think in the long run, they will save you both money and time.
How can I make my aquarium plants grow faster?
To make your aquarium plants grow faster you have to provide them the ideal environment that they require.
Basically, you have to provide them the optimum lighting conditions.
Provide them a nutrient-rich substrate if necessary or add nutrients through tabs if you already have a gravel or sand substrate.
And thirdly, maintain ideal water parameters and do regular maintenance that is removing dead leaves and providing fertilizers on a regular basis.
If you do these things then your aquarium plants most likely grow faster.
Can aquarium plants grow without fertilizers?
Yes, there are some aquarium plants that are very hardy and can do well without any fertilizers in your aquarium.
I have written a detailed article covering all these plants in this article.
But without fertilizer most aquarium plants will not thrive in your tank.
Though there are some hardy plants that will survive and grow, they will not be at their best without fertilizers.
What nutrients do aquarium plants need?
Aquarium plants require several micro and macro nutrients for their proper growth.
They require micronutrients such as nitrogen, potassium, and phosphorus in large quantities.
Besides, they also require micronutrients such as boron, magnesium, iron, copper, potassium, zinc, etc in small quantities.
How long does it take for root tabs to work?
If you are not using any fertilizers then after adding root tabs you should notice some improvement in your plants within a couple of weeks.
Root tabs release nutrients slowly into the substrate and they usually last for 3 to 4 months. So to see a significant improvement, you may need to wait for a couple of months.
Should I remove dead plants from my aquarium?
Yes, you should definitely remove dead plants from your aquarium because if you don’t do so they will decompose in your tank.
In the process of decomposing, they will produce a lot of ammonia which can be deadly for your fish.
Can too many plants kill fish?
Yes, too many plants can kill fish. But for a normal aquarium, it is unlikely that your fish will get killed because of plants.
The only scenario your fish can get killed due to plants is when you have a lot of plants i.e. heavily planted tank and you don’t have any setup to maintain oxygen during the night.
The thing is if you have a lot of plants in your tank, then at night, they will produce a lot of carbon dioxide. And this can cause oxygen deficiency in your tank during the night which can kill your fish.
So the way around it is to introduce an air pump and keep it on during the night.
The air pump will keep your tank well oxygenated during the night so your fish will not get killed due to oxygen deficiency.
Overall, aquarium plant fertilizers are safe for fish as far as you are not overdosing them.
Fertilizers do contain some elements that can be harmful to your fish but they are in very less amount.
But if you overdose your plants with fertilizers then this can increase the quantity of harmful elements in your tank which can be harmful to your fish or invertebrates in your tank.
I hope you found this article helpful.
If you do, please share it.