A once flourishing aquarium plant now turning a ghastly brown can make any aquarium owner feel hopeless. No aquarist is immune to the slow descendent of your plants turning brown, beginning to rot, and fouling your water. Although aquarium plants turning brown is a common issue, there is no one definite cause. You will have to test, examine, and determine the reasoning behind this unsightly occurrence.

Once you look through the possible reasons for what is occurring in your aquarium’s environment, you will be able to pinpoint the reason and formulate a solution. We have compiled information on the common causes of aquarium plants developing brown leaves to help you figure out the possible culprit behind this dreaded change.divider3 goldfish bowl

Factors That Turn Aquarium Plants Brown


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Brown leaves are a sure sign something is not right in your plant’s aquarium environment, and this is affecting your plant’s overall health and coloration. This leads the plant to slowly decay and display an overall unappealing appearance.

There are a few causes, namely:
  • Poor Water Quality Just like the aquarium’s inhabitants, plants require good water quality too! Although aquarium plants are added to tanks to maintain a good balance of water quality and keep the parameters under control, the plants themselves need adequate conditions to grow and thrive. If a plant is left to control water conditions with a tank carrying a high bioload, the plant will begin showing signs of browning and will start decaying at a rapid pace.
  • Stress Plants that experience constant requirement imbalances start to have decaying leaves and poor growth. If this continues for some time, the plant’s leaves will start to turn brown and die off. Plants need steady water temperatures, a stable pH, and the plant’s ideal lighting requirements.
  • Lighting Each species of plant requires its own lighting requirements, whether low or high lighting. It is important to make sure you research the conditions and lighting your plants require to ensure they don’t die off from incorrect lighting in your aquarium.
  • Chemical Additives When it comes to adding chemicals and medications to your aquarium, it is important to ensure that the container says it is safe for use with aquarium plants. Some chemicals made for aquariums can kill off plants. This occurs from the chemical burning the plant’s roots, leading to poor nutrient absorption and the development of brown leaves. These leaves can start to decay, which will eventually decay and foul your tank’s water.
  • Oxygen Availability — Aquatic plants need sufficient oxygen to carry out photosynthesis and remain healthy. When an aquarium lacks oxygen and your plant has to compete for oxygen in the water with your inhabitants, it will lead to poor growth. This develops into the plant displaying brown and decaying leaves. Your plant will then remain with brown leaves until oxygen is added to the water at appropriate levels.
  • The Number of Plants- Keeping a fair number of plants in your aquarium leads to a variety of plant species competing for essential nutrients within your aquarium. The dominant plants will absorb the nutrients naturally produced in your aquarium, leaving weaker and more vulnerable plants to develop brown leaves.
  • Substrate Different plant species require different substrate types. Few plants root well in gravel. The roots do not develop, and this leads to your plant slowly dying. Without the roots being able to establish appropriately, your plant cannot obtain nutrients. Most plants do well in a nutrient-rich sand substrate, with enough substrate layered for the plant to root.
  • C02 and Fertilizers Plants require the occasional additive of aquatic plant fertilizers, root tabs, or C02. This ensures your plants receive sufficient nutrients to grow and develop properly. If the tank is low in nutrients and you do not add supplements, your plant will slowly develop brown leaves as a result of poor nutrient intake and slow growth.
  • Water Temperature Plant species are either adapted to living in cold, temperate waters or heated, tropical waters. Plants that naturally survive in cold water will have a hard time surviving in warmer water. This leads to the development of brown leaves. It is essential to keep your species of plants in the right tank environment.
  • pH Levels All plant species require a different pH level in the water. Some plants require a softer and acidic environment and other plants prefer harder water with a high pH value. Adding aquarium pH enhancers or pH decreasing agents into the water to obtain the recommended pH for your plants is essential to ensure against browning and decay.
  • Pests and Disease When you bring your aquarium plant home, you may be unaware of pests on the plant that can spread disease or consume your plant, such as snails. This can lead to discoloration and eventual decay.

Tips To Stop Your Aquarium Plants From Turning Brown

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When it comes to aquariums, preparation is key. Before acquiring an aquatic plant, make sure you do in-depth research on that particular plant’s environmental requirements. This is recommended as one of the best solutions to keeping your aquarium plants healthy.

  • Regular temperature monitoring, water testing, and the addition of occasional supplements will have browning leaf plants perk up into a lively and healthy plant. Make sure to inspect and quarantine all newly acquired plants for pests and signs of disease. This ensures the pests or diseases do not affect the rest of your aquarium life.

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Browning plants can be disheartening to aquarists, but we hope this article helped you gain some idea of why your aquarium plant is turning brown. To prevent your plant from rapidly decaying, acting fast and steadily to meet the plant’s growth requirements will ensure it remains healthy and thriving.

Featured image credit: jurgko, Pixabay