Why Do Aquarium Plants Die? [9 Main Reasons]

Image of a dying aquarium plant

Aquarium plants are a great addition. They brighten up the aquarium with their natural beauty and benefit the fish by creating a thriving ecosystem. However, live plants are prone to diseases, water changes, and stress. So, why do aquarium plants die?

Given below are the 9 main reasons why aquarium plants die:

  1. Improper water pH,
  2. Excessive or lack of lighting,
  3. Excess filtration,
  4. Substrate instability,
  5. Left-over food,
  6. Fish waste,
  7. Unsuitable fertilizer,
  8. Incorrect tankmates, and
  9. Nutrient deficiencies.

Let’s now discuss each one of these reasons in detail.

9 Main Reasons Why Aquarium Plants Die

Aquarium plants need maintenance.

You cannot simply buy aquarium plants, place them in your aquarium, and hope they will thrive on their own.

Without proper care and maintenance, you will find your plants dying sooner than later.

Following are the primary reasons which, if overlooked, can cause the death of your aquarium plants.

1. Improper Water pH

This is one of the primary causes of aquarium plants’ death.

According to the type of aquarium plant, the ideal pH level should be in the range of 6.5 to 7.8.

Water pH plays an essential role in the well being of your plants.

If water pH is not ideal, it will adversely affect the growth of your plants.

Also, algae and other harmful substances can grow in your aquarium water if the pH is incorrect.

These are silent killers that will harm your fish and deteriorate plant life.

2. Excessive Or Lack Of Lighting

Adequate light is essential for fish as well as plants. Plants cannot survive without light for too long.

Aquarium plants need light to photosynthesize and create vital nutrients that are essential for their growth.

Lack of lightning adversely impacts the plants and results in fading and eventual death.

This doesn’t mean that more lighting is good for aquarium plants. Excessive lighting hampers the growth of aquarium plants.

Too much light also increases the growth of algae in the aquarium. Algae are not too good for your plants.

Along with lighting, the wattage of the light also plays a significant role. The light wattage should be adjusted as per the tank size.

Ideally, two to three watts of lighting per gallon of water are required to properly grow aquarium plants.

3. Excess Filtration

Filtration is an integral part of any aquarium. However, excessive filtration is not suitable for aquarium plants.

Plants need carbon dioxide to grow.

Excessive filtration filters out a lot of carbon dioxide from the water, which isn’t appropriate for the plants at all.

Lack of carbon dioxide deteriorates plant life and can even lead to the death of your aquarium plants.

4. Substrate Instability

Substrate plays an equally vital role in the growth of aquarium plants.

It lies at the bottom of the aquarium and consists of pebbles, stones, and gravel.

A substrate is a means of survival and growth for your plants.

If the substate is not ideal for the plants, they will not grow and will eventually die.

For example, if the gravel is broad, it will adversely impact plant life.

The gravel will have too many spaces in between, and so it will not be able to firmly hold the aquarium plants’ roots.

Instead of being firmly grounded on the substrate, the aquarium plants will uproot and float in the water.

That is why the aquarium substrate should be fine enough to hold the plants firmly.

This will help them absorb the essential nutrients.

5. Left-Over Food

Left-over food is another primary reason for aquarium plants to die.

It contaminates the water if not removed immediately. Polluted water is a major threat to aquatic plants.

Left-over food not only contaminates the water but also breaks down and gets absorbed by the plants.

This is highly dangerous as it imbalances the ecosystem of the fish tank.

6. Fish Waste

Just like left-over food, fish waste also damages the plants. Feeding plays a role in this case.

If you feed more food than what is required for your fish, it will result in more waste.

Fish waste contains certain chemical compounds that are harmful to plants.

Besides, if fish waste is not cleaned immediately, it releases chemicals that hinder plant growth.

7. Unsuitable Fertilizer

Fertilizer is needed so that aquarium plants can stay strong and healthy. It helps in enriching the plants from their roots.

Besides, a fertilizer contains the macronutrients that plants need for their optimum growth.

Unsuitable or lack of fertilizer causes plants to wilt. It will make plants unhealthy, turn their leaves yellow, and kill them eventually.

8. Incorrect Tankmates

Fish are a real treat to watch. Along with aquarium plants, they liven up the tank with their bright colors.

However, they can also be a reason for the premature death of aquarium plants.

Some fish like to nibble on plants every now and then.

While some other fish try to pull out the plants from their roots, causing them to float on the surface of the water.

Certain fish such as Tetras, Cichlids, and Silver Dollar are aggressive plant-eaters.

If you have an aquarium with fish that love to eat plants, your plants will not survive for long.

So, when you think of having plants in your aquarium, you should be well aware of the fish in your tank.

9. Nutrient Deficiencies (Nitrogen, Potassium, Phosphate, Iron, Calcium, Magnesium)

Aquarium plants need an adequate amount of nutrients to stay healthy and live longer.

Nutrient deficiency can lead to stunted growth, dying tissues and can be a big reason for your plants’ death.

On the other hand, an excessive supply of nutrients like nitrogen, potassium, and phosphorous also hinders plants’ growth.

Deficiency of essential nutrients such as nitrogen, potassium, phosphate, iron, calcium, and magnesium for a prolonged period hampers aquarium plants’ growth.

This can eventually result in the death of your plants.

Nitrogen deficiency turns aquarium plants yellow.

You can notice the difference in the color, especially in the old leaves. Another sign is smaller new leaves or crippled growth.

Deficiency of potassium results in distinctive pinholes in the plants’ leaves.

Initially, you can notice small black dots. These will soon turn into visible holes, partially outlined in black or yellow.

Just like nitrogen, phosphate is another macronutrient that plants consume in large quantities.

In the case of phosphate deficiency, the older leaves will start turning yellow with soggy brown patches.

You can even notice green spots of algae on dying leaves as they begin to break down.

On the other hand, iron deficiency is easily visible and recognizable.

Iron deficiency results in the fading of green leaves.

The new leaves will fade to pale yellow, and they will start to look like old leaves.

Calcium deficiency is yet another concern.

If you notice new leaves growing in a twisted manner, your plants either lack calcium, or they are suffering from some water hardness issues.

Magnesium deficiency is similar to iron deficiency.

The only difference is that it impacts the older leaves, unlike the newer leaves in case of iron deficiency.

You can notice older leaves turning light in color with dark veins.

Related Further Reading:

How To Tell If Your Aquarium Plants Are Dying?

Plants show various signs before dying. You need to closely look for these signs to prevent your plants from dying.

Nutrient deficiency plays a vital role in identifying the signs of a dying plant.

Given below are various signs that can help you identify if your aquarium plants are dying:

  • Live plants need adequate nutrients to thrive and grow. If your plants are dying, the signs will first show on their leaves. Your plants will start losing color and will begin to fade.
  • The growth of your plants will get slow compared to when you had planted them.
  • The majority of the live plants have green color leaves. So, if your plants’ leaves start turning yellow, it is an early sign of nitrogen deficiency.
  • If you observe holes in your aquarium plants’ leaves, it is a clear indication that your plants are not healthy and can soon die. Excess nitrate and poor water quality are the culprits here.
  • You may notice the twisting of the new leaves of your aquarium plants. This is a sign of calcium deficiency.
  • Brown spots on the leaves of your aquarium plants are a sign of phosphate deficiency.
  • If your aquarium plants produce tiny leaves, they lack nitrogen.
  • The overdose of magnesium or potassium can also lead to twisted leaves. This is another indication that your plants are dying.

Alright! Now that you know how to tell if your aquarium plants are dying, let’s understand if this affects the fish.

Can Dying Aquarium Plants Kill Fish?

Dying aquarium plants can kill fish. Plant decay leads to ammonia build up in the aquarium.

Due to the ammonia built-up, nitrite gets created in the aquarium water. A high nitrite level is poisonous to the fish.

Besides, water also gets contaminated due to the dying plants.

Dead plants rot if they are not removed immediately from the aquarium. Contaminated water is another reason for the fish to die.

One more reason for the fish to die is the debris.

If dying plants are not properly taken care of, it leads to floating dead plant debris in the aquarium water.

This impacts the health of the fish.

Should You Remove Dying Plants From The Aquarium?

Dying plants should be removed immediately from the aquarium.

Dying plants have an adverse effect on the fish. They also impact the other live plants in the aquarium.

Once a plant dies, its leaves begin to fall. The leaves that fall on the gravel deprive other live plants of the required nutrients.

Besides, the fallen leaves contaminate the aquarium water.

Bacteria can build up in the aquarium water due to the fungus created by the fallen leaves.

Interesting Further Reading:

Final Thoughts

Aquarium plants are hardy in nature. This does not mean that they can thrive in unsuitable conditions for a long time.

As discussed above, aquarium plants can die due to various reasons.

Excessive lighting, filtration, left-over food and fish waste, unsuitable fertilizer, notorious tankmates, and nutrient deficiencies are common reasons for your aquarium plants to die prematurely.

Luckily, plants do not die suddenly.

They show various signs before dying that indicate they are not healthy and need your attention, care, and maintenance.