Nutrient Deficiencies: Different Symptoms in Aquatic Plants
Written by: BP Team member Simon Zhu (@sz_aquatics)
Do you have a tank with perfect lighting, CO2, and water parameters, but still having trouble with plant health? Have you noticed that your freshwater aquatic plants aren’t looking healthy for some reason? Are your aquarium plants mysteriously dying and you can’t quite figure out why?
It’s possible that your planted aquarium is missing one or several necessary micronutrients that are important for plant growth!
Micronutrients are essential vitamins and minerals needed for all living organisms to have healthy growth and immunity. We will be reviewing the different types of plant nutrient deficiencies (iron, calcium, nitrogen, phosphorus, potassium, manganese) and how to fix them.
It’s important to note that dosing a fertilizer, such as UNS All-In-One Liquid Fertilizer, is a great way to start providing micronutrients into your aquarium. Doing so can prevent nutrient deficiency in your planted tank!
In a heavily planted aquarium (especially when stocked with fast growing plants) some micronutrients may be depleted faster than others. As a result, your tank can be deficient in a certain necessary micronutrient. Some examples of fast-growing plants are Ludwigia Arcuata, S. Repens, and Rotala Rotundifolia.
- Note: Many of the damage patterns from nutrient deficiencies listed below are similar to a CO2 deficiency. First consider your plants’ carbon dioxide intake before other nutrient factors. Remember that CO2 is crucial for healthy plant growth. You should only treat your plants for the below deficiencies if you can rule out a lack of CO2.
The solution sounds easy, simply dose whichever nutrients is deficient, right? Technically yes, but the first and most crucial step is to identify which micronutrient is deficient. Sometimes identifying this can be the hardest part!
We will go over each micronutrient, what plants use them for, and how the plant will appear and grow if there is a deficiency. Team Buce Plant is here to help you recognize the signs of nutrient deficiency in your aquarium plants so you can save them before it’s too late!
Deficiencies Seen on New Leaf Growth
The two nutrient deficiencies below will appear on new leaf growth.
If plants are iron deficient, the newer leaves will grow in a pale light green, yellow, or even white with no abnormal spotting, while older leaves will appear normal. The veins of the new leaf growth will remain dark compared to the discolored leaves.
Iron is used in several enzymes and pigments. Enzymes help plants to produce energy and iron is essential in the formation of chlorophyll.
Make sure to use an iron-specific supplement to treat plants with an iron deficiency such as UNS Plant Food Liquid Iron. There will not be high enough concentrations of iron in all-in-one fertilizers.
A calcium deficiency will result in new leaves growing out twisted and stunted, while the tips of the leaves may wither.
Calcium is used in the plant’s cell wall production process and is a crucial component of a structurally stable cell wall.
A calcium deficiency may be a result of using soft water or RO water in your planted aquarium. It is recommended to gradually increase your water’s hardness by adding crushed coral in your filter or sprinkling it on top of the substrate. Although, calcium deficiency is rarely an issue in freshwater aquariums.
Deficiencies Seen on Older Leaves
The five nutrient deficiency signs below will appear on older leaves first before spreading to the entire plant.
Signs of nitrogen deficiency will first be seen in older leaves. The leaves will turn yellow and translucent starting at the tips. Leaves may begin to fall off starting with the oldest leaves.
This is because nitrogen is a vital component of chlorophyll, the main pigment used by plants to produce energy. Nitrogen deficiency may become a problem in planted aquariums with little to no livestock.
Nitrogen deficiencies are common amongst beginners in the hobby. A nitrogen deficiency is typically not a problem in aquariums with an established nitrogen cycle. A cycled tank that is stocked with fish or shrimp will have plenty of nitrogen for your plants. These living animals will produce waste that will be cycled into nitrogen for plants to consume. Click here to learn more about how to cycle your tank.
Also, plants may experience nitrogen deficiency because they aren’t getting enough fertilizer anymore. Keep in mind that as your plants continue to grow larger and more lush, they will need more fertilizer. Up the dosage over time in order to match your plants’ growth as they fill your tank over time.
- Note: If you notice yellow or translucent leaves on a new addition plant in your aquarium, this is most likely a sign of melting, not nitrogen deficiency. Bucephalandra, crypts, and stem plants are known for melting in new environments, but will eventually bounce back with new submersed-grown leaves. Your plant could simply be adapting to its new environment. Allow your newly added plant some time to get accustomed.
These leaves will start to appear darker than usual and with a brown appearance on the underside. Leaves will then turn completely yellow with soggy melt-like brown patches. Then, the dying leaves will usually form algae. The new leaves typically grow shorter and may even be distorted. Stems will grow to normal lengths but be much thinner compared to a healthy plant.
This deficiency can be caused by using phosphate-absorbing pads, which some aquarists use to try and combat algae. Although, this could potentially starve your plants of the phosphate they need.
A phosphorus deficiency will be first seen in older foliage because plants need to consume it in large quantities. Phosphorus is used to make ATP, which is the energy source of most living organisms. The key component of ATP is phosphorus, so without phosphorus there will be no ATP... No ATP means not enough energy for normal physiological functions such as proper growth!
A plant with a potassium deficiency will have small pinholes on the leaves, mostly concentrated at the edges and tips. Sometimes the edges may appear pale and curl inward.
Potassium helps with the movement of nutrients, waters, and sugars throughout a plant. Certain plants such as anubias or java fern need lots of potassium to survive. Treatment for potassium deficiency can easily be fixed by dosing your tank with an all-in-one fertilizer.
Plants that are deficient in Manganese will have yellow to white reticulated patches on the leaves.
Manganese has a key role in plant physiology, particularly in photosynthesis.
Keep in mind that some species, such as Anubias Pinto or Anubias Nana Petite White, have leaves that naturally have light colored patches and dark veins. Make sure to understand the difference between a variegated plant (that’s supposed to have white patches) and one that is manganese deficient.
A deficiency of magnesium will cause leaves to turn lighter in color while the veins stay dark. This is similar to an iron deficiency, but a magnesium deficiency will be seen in the older leaves. The edges of the leaves may begin to droop. This deficiency is sometimes related to a calcium deficiency. Magnesium is already in most aquatic plant fertilizers, so simply make sure you have a fertilizer regimen.
Now that you’re equipped with this knowledge, it’s time to identify which micronutrient is deficient in the aquarium and start solving the problem!
How you’re going to save your plants depends on what nutrient deficiency they are suffering from. Keep in mind that whether it’s adding fertilizer, increasing water hardness, or removing some plants, it will take time to see a difference in your plants’ health (about 2 to 3 weeks.) Just be patient! After you’ve waited to see if your solution has helped with the suspected deficiency, you can perfect your fertilization schedule to match what your plants will actually consume.
The most common micronutrients that become deficient are iron, potassium, and phosphorus.
Many of the nutrient deficiencies above can be solved by adding all-in-one fertilizers. There are liquid forms of each micronutrients, such as UNS Liquid Iron Fertilizer, that can be used in conjunction with an All-In-One fertilizer to address any deficiencies. We always recommend reading the dosing instructions before using any type of fertilizer, and then adjust the dosing amount according to the needs of the aquarium.
Remember: your planted tanks are constantly changing! After all, you have created your own ever-changing ecosystem. It’s important for the health of your tank to keep your plants pruned and be consistent with your water changes. During your pruning, take note of your plants’ health and jump on any suspected nutrient deficiencies.