When Should I Dose Iron in My Planted Aquarium?

Just as people need certain nutrients to function correctly, aquatic plants require a unique mix of fundamental building blocks to live and grow. Macronutrients (like nitrogen, potassium, and phosphorous) are nutrients that plants consume in large quantities, where as micronutrients (like iron and boron) are nutrients that plants consume in trace amounts. Easy Green, an all-in-1 liquid fertilizer, already contains iron (Fe). So when do you need to add more iron to your plant tank?

Are my aquarium plants in need of more iron?

Plants use iron to make chlorophyll. This is a green pigment that absorbs light and makes energy. In general, plants that are fast-growing or need bright lighting use lots of energy. In order to get more energy, they often require supplemental iron to produce an abundance of chlorophyll. An increase in iron can help your plants grow stronger and produce more vibrant colors.

Are my aquarium plants iron deficient? Iron cannot move freely from one part of the plant to the other. Consequently, if your aquarium is low in iron, the newest leaves on the plant look pale or yellow from insufficient chlorophyll, whereas the old leaves still retain their bright colors.

Plants lacking iron might show yellowing or pallor on their newest leaves, with veins that are darker in color.

Do red plants need iron? Iron primarily helps to create green chlorophyll pigment and not red pigment. Red plants such as scarlet temple and Ammannia gracis may need extra iron, since they are high-light plants that consume higher amounts of nutrients. Scientists are studying the function of red-leafed plant red pigments. These plants have higher levels of red chlorophyll than green chlorophyll. Under intense lighting, the red pigment may serve to protect leaves from excess light energy, and the amounts of green pigment may be decreased since not as much chlorophyll is needed to collect light photons. We recommend that aquarium hobbyists use a combination of high-light, carbon dioxide (CO2) injection and good nutrient doses (including iron) in order to increase the redness of their plants.

With certain red plants, the highest leaves may turn pink, red or purple depending on where they are located. However, the lower leaves remain green in the shade.

Bottom line: if your planted aquarium isn’t displaying nutrient deficiencies and you aren’t trying to grow high light plants, you probably don’t need to add any extra iron beyond what comes in Easy Green fertilizer. Supplemental iron is not required if you have iron-enriched substrate or well water. However, if your tank has greater iron demands than what is currently being provided, keep reading.

How Often Should I Add Iron to My Aquarium?

Easy Iron is our iron supplement for enhanced plant growth that is completely safe for aquarium fish, shrimp, and snails. This highly concentrated iron blend is derived from iron DTPA, ferrous gluconate and iron EDTA. Iron is very efficient in aquariums. Therefore, we recommend that you use 1 ml (1 ml), of Easy Iron per 10 gallon of water approximately every 1-3 days as needed. Each pump contains 0.26 ppm iron and a whole bottle can treat up to 5,000 galallons of water.

Start with a low dose and increase gradually over the next two weeks if you are unsure. People have reported an increase in filamentous or hair algae when an excessive amount of iron is used. A few articles on planted tanks recommend that you aim for an iron level of between 0.1 and 0.5 ppm in your aquarium water.

Why does Easy Green not contain more iron? Easy Green fertilizer is already a good choice for most planted aquariums. It contains trace amounts of iron. Easy Iron is a separate product that can also be added to other nutrients and minerals.

If you are having problems with your live aquatic plants and they do not appear to be caused by a lack of iron, check out our full article that describes other plant nutrient deficiencies to see if any of the symptoms match. Enjoy your tank and good luck!