Why Are My Aquarium Plants Turning Yellow? Common Nutrient Issues Solved by AquaBed

When growing plants in your aquarium, there are some common problems you might encounter. One question often asked is “Why are my aquarium plants turning yellow?” As is true with any kind of gardening or landscaping, one question begets another, and the root cause of an issue could be one or several factors. In this case, yellowing leaves on aquarium plants could be the result of several core issues, including nutrient deficiencies. What nutrient deficiencies could cause yellowing leaves in plant aquascaping?

Nitrogen Deficiency: Frequent water changes without checking on nitrate levels could result in too little nitrogen being available to the plant. Nitrogen is essential for leafy growth and deep, green color, and without it, leaves will typically appear pale, yellow, and sickly. If you are regularly fertilizing and monitoring nutrient levels, but plants still have yellowing leaves, it could simply be that the plant has outgrown the current dosing and you need to fertilize more.

Iron Deficiency: If you’re noticing that leaves are pale yellow but retain green color in their veins, you could be seeing a clear sign of chlorosis, or iron deficiency. Special iron supplements can be used to rectify the situation. Iron deficiency is most common on the newest growth.

Potassium Deficiency: Yellowing that’s focused in small areas and surrounding a pinhole in the plant’s leaf could point to a potassium deficiency. Certain plants need more potassium than others, and fertilizers can be used to increase potassium levels in planted aquariums.

Phosphate Deficiency: Phosphate is the last of the “big three” macronutrients that plants require for healthy growth. Oftentimes, phosphates available in other inputs like fish food can supply all the phosphorus needed, but at times, there may be a deficiency. Older leaves are typically affected the most, and may turn yellow and brown.

Magnesium Deficiency: More common on older leaves, magnesium deficiency looks much like a lack of iron, with dark veining on a pale, yellow leaf. In this case, though, it is the older leaves that are typically affected. You may notice leaf drooping as well. A complete fertilizer will typically include all of the magnesium needed.

Calcium Deficiency: A lack of sufficient calcium can result in malformed leaves and can point to a water hardness issue. In this case, it is recommended to use special calcium salts to provide the necessary calcium for your plants.

Beyond these main nutrients, sulphur, oxygen, and hydrogen are also vital. Micronutrients that plants may require can include boron, zinc, copper, molybdenum, silica, vanadium, selenium and cobalt, depending on the species of plants growing in your planted aquariums. 

How to Fix Nutrient Deficiencies in Aquascaping

In conjunction with each specific supplement deficiency, fertilizers are commonly used to address all sorts of nutrient deficiencies in planted aquariums. However, figuring out just the right dosing can be tricky, and you could end up doing more harm than good in your aquarium. While using a complete or all-in-one fertilizer is still a perfectly viable option, easier still is using a soil source that provides all the nutrients that your plants need to thrive. AquaBed does just that, and can sustain plants for a year or longer! Your plants will be happier, and the other living organisms in your tank won’t be affected at all. When your plants stop sending out new growth and start to look sickly, you’ll know that it's time to change or add soil.

 Micronutrients and Lighting for Your Aquascape

Beyond ensuring proper levels of major macronutrients and additional micronutrients and trace minerals, another reason why you’re seeing yellowing leaves in your aquascape could include a phenomenon called melting. What is melting in regard to aquarium plants? This is especially common on new plants that are adjusting to your planted aquarium and were not originally being grown underwater. Old leaves will melt away, making room for new, healthy leaves that are adjusted to their new environment. Even if plants were grown submersed, they may have to adjust to the nutrient profile of your tank, and melting may help them to achieve that. New leaves should be well-acclimated, and the plant should grow well once recovered and fully transitioned. If you continue to experience issues with melting, consider dissolved carbon dioxide supplementation to aid in photosynthesis.

Your aquascape lighting situation can also affect your plants' growth and whether or not they will thrive or start growing leggy or yellowing. You may be able to correct what looks like a nutrient deficiency by adjusting or adding more powerful aquarium lighting that allows the plant to better photosynthesize. A plant that seems to stretch toward your light source and is very limp and peaked could be showing you that it needs a stronger light that is closer to its leaves.

Algae overgrowth could be a sign of nutrient imbalance, and algae can also compete with your aquarium plants. Proper light levels will encourage plants to grow stronger and faster, and this, paired with timely removal of excessive levels of algae will help to ensure that nutrient levels are at the right levels for plants. Proper amounts of food for any fish or other animals in your planted aquarium can also help to prevent nutrient levels from getting out of balance and jeopardizing plant health.

All in all, it is important to remember that nutrients do not always work independently–more often than not they are working synergistically to maintain aquarium health. A holistic approach to tank management is generally a best practice.

Successful Aquascaping With AquaBed

Clearly, soil matters when it comes to growing plants underwater! No matter what aquatic plant you choose, if you utilize the well-balanced, robust nutrient profile contained in every AquaBed packet, you can relax and enjoy your planted aquarium, knowing that your plants are growing well and providing a healthy and calming living environment to your fish and any other aquatic creatures. 

Now that you understand why soil quality is so important to planted aquarium success, it’s time to get planting and growing! Check out our list of five easy aquarium plants for beginners to get you on your way.

See for yourself the difference that AquaBed makes and get your own to start aquascaping today!