Nutrient Deficiencies: Why Your Aquarium Plants Are Dying

You have the perfect aquarium, but your plants keep dying. It could be from a lack of nutrients. Even if your plants are receiving regular fertilizers, they might be missing essential building blocks that hinder their growth and thrive. We will show you how to identify the signs of nutritional deficiencies and help you take preventative measures to ensure your plants don’t die.

Example of a healthy and normal leaf

Different types of plant nutrient deficiencies

Nitrogen Deficiency

Low nitrates are a common problem in planted tanks, especially with beginners in the aquarium hobby who have been taught to do routine water changes every week (without testing for the actual nitrate level). This habit, while fine for fish only tanks, can lead to a lack of nitrogen, even if you are regularly dosing fertilizers. Classic signs of nitrogen deficiency include old leaves turning yellow and translucent, especially starting at the leaf tips, as the plant consumes nutrients from its old leaves at the bottom in order to make new leaves at the top.

Signs that old leaves may have a nitrogen deficiency

Another reason that you could run into nitrogen shortage is that you have been following recommended fertilizer dosing guidelines, but four months later your plants have tripled in size and you are still giving them the same amount. Just as you automatically feed more food if you add more fish to an aquarium or if they grow bigger over time, you need to feed your plants more as they get taller or propagate.

The same principle applies if you prune or remove a bunch of plants – make sure to lessen the amount of nitrogen provided. We recommend that you match the fertilizer that you use to your plants’ growth, whether it is liquid fertilizers that are used for plants that rely on the water column or root tabs that are used for plants that rely on their roots.

Now, if you see yellow or translucent leaves on a brand-new plant that was recently added to your aquarium, this may be a sign of melting, not nitrogen deficiency. Many plants bought online or locally were grown in water. These emersed leaves will eventually melt to make way for smaller, healthier, submerged-grown (or underwater) leaves. This melting effect could occur even if you buy a submerged-grown plants from another hobbyist. It is because the plant needs to adjust to the different water parameters of your tank.

For example, stem plants that are melting tend to lose their lower leaves, leaving a bare stem on bottom with new leaves on top. Once the stem has completely transformed to only submerged-grown leaves you can remove the top and replant it. Amazon swords, cryptocoryne and stem plants are well-known for melting in new environments. However, anubias or java ferns are more resistant.

Iron Deficiency

Plants lacking iron can show yellowing of their newest leaves, as well as leaf veins that stay darker in color. The older leaves, on the other hand, usually look normal.

Signs of iron deficiency in new leaves

It can be difficult for iron to be incorporated in common fertilizers. So instead of buying more fertilizer that is all-in-one, consider purchasing an iron-specific product to treat your plants. You can also increase the color of red plants by adding extra iron.

Potassium Deficiency

This condition is easy to diagnose because the plant’s leaves will develop distinctive pinholes that are sometimes rimmed with brown or yellow. Certain plants like java fern and anubias thrive in environments with more potassium, so watch out for those signs. While you can buy a potassium-specific product, Easy Green has been fortified with extra potassium to solve such issues. It is easy to simply add more of our broad-spectrum fertiliser.

Signs a potassium deficiency in old leaves

Phosphate Deficiency

A macronutrient, like nitrogen, that plants consume in large amounts is phosphate. Therefore, the older leaves are most affected and will start turning yellow with soggy brown patches. When the dying leaves are being broken down, they may develop green spots. This condition is more uncommon, since fish foods like flakes contain phosphates. Sometimes, however, people will use phosphate absorb pads to stop algae growth in their filters. This causes the plants to become starved.

Signs that old leaves have a phosphate problem

Magnesium Deficit

Magnesium deficiency is similar to iron deficiency. The leaves become lighter with darker veins due to lack of iron. But in this case, it affects older, not newer leaves. Sometimes the leaf edges can droop. Magnesium is a common ingredient in general-purpose fertilizers. You can either add more magnesium to your fertilization regimen or use Epsom salts or a magnesium supplement to get this nutrient. This condition can often be linked to calcium deficiency.

Signs that old leaves have magnesium deficiency

Calcium Deficiency

If you see new leaves growing in a twisted, gnarled fashion, this is usually related to a calcium or water hardness issue. Low water hardness is often a sign of calcium, magnesium, or manganese deficiency. These minerals may be required to maintain the health of your crystal shrimp or discus if you have soft or RO/DI water. By adding crushed coral to the aquarium or filter, Wonder Shell, Seachem Equilibrium mineral supplements, and Wonder Shell, you can gradually increase calcium levels.

Signs that new leaves may have calcium deficiencies

How to Fix Nutrient Deficits

In order to properly treat your plants, identify the nutrient deficiency and how you’re going to fix it (e.g., add more fertilizer or specific supplements, increase the water hardness, feed more fish food, and/or remove some plants). If you do decide to use more fertilizer, ensure it contains the required nutrients. Easy Green does not affect water hardness, calcium, or other levels.

You can solve most deficiencies by increasing your intake of all-in one fertilizers. For instance, if you are missing nitrogen, it is likely that you are also missing other nutrients. Your plants will soon run out of nutrients if you only give them a nitrogen supplement. Easy Green Tabs and Easy Root Tabs provide more of the macronutrients that your plants require (in the right quantities).

Simple Green is our recommended fertilizer. This fertilizer was initially developed for use in our retail store. It is easier to use than other supplements, has a higher nutrient concentration and is affordable. The all-in-one liquid fertilizer provides all the nutrients that aquatic plants need to thrive. Unlike other ammonia-based fertilizers, Easy Green is completely safe to use with fish, shrimp, snails, and other invertebrates.

It generally takes two to three week for you to notice any changes in your plants. This will allow you to determine if your actions were beneficial or detrimental. Based on the results, tune your fertilization schedule to match what the plants actually consume. Because plants change over time, fertilizer needs will need to be adjusted as they grow. Leaves can be pruned and plants added or removed. If you want your planted aquarium to thrive, make sure you regularly inspect it and spot any deficiencies.

Take our free infographic about plant nutrient shortages here for a quick reference.