Identifying Aquarium Plant Deficiencies

Unlike most other living beings that survive on oxygen, aquatic plants essentially live on CO2. As they don’t get enough of it in tanks, we have to inject it there. Another essential item for the aquarium plant survival is light because that is the medium thru which they process their food. This process is called Photosynthesis. NO light means no photosynthesis and thus no food for your plants and their eventual death. So we have to maintain a balanced diet by adjusting these two elements.

As in the case of humans, a deficient diet reflects on their health, so is the case with aquatic plants. In both the cases we look for symptoms to know which nutrient is deficient. If you are already handling plants you might have observed that a low growth is generally caused by insufficient light or co2. In such plants it becomes a bit too difficult to realize other deficiencies as the symptoms are not so apparent. On the other hand in high growth planted tanks with lots of light and plenty of co2, aquatic plants grow so fast that there is a depletion of nutrients.

So far we have not been able to develop a scientific system to accurately measure the quantities of nutrients present in a given aquarium plant. So, we go by the Symptomatic Treatment. Before proceeding further, it will help you know that some of the nutrients are mobile while others are immobile. Mobile means that the plant can reclaim nutrients from old leaves and move them towards producing new leaves.

Nitrogen, phosphorus, potassium magnesium and zinc come in this category. Deficiency of these nutrients appears on old leaves. But immobile nutrients cannot be moved from older leaves. Immobile nutrients comprise of boron, calcium, copper, iron, manganese and sulfur. Deficiency of these nutrients will appear on new leaves.

At times one warning signal may be indicative of deficiencies of more than one nutrient while at other times one insufficiency may disguise the other one. Since leaves are the most visible, you should look for signs of deficiencies around those on the aquatic plant. Next you should observe if the leaves being affected are new or the older ones.

The above observations coupled with a study of the following table may prove to be a good helping hand for you in your analysis of the aquarium plant-related deficiencies.

ElementFirst Signs appear on old/New LeavesSymptoms
BoronNewDelicate or brittle stems, dead shoot tips
Carbon DioxideNewSlow/retarded growth of leaves which may have calcium deposits
CopperNewDead leaf tips
IronNewPale growth of new leaves followed by yellowish color, leaves may become brittle
Magnesium(Mg)OldYellow spots or yellowing of leaves around edges; generally similar to iron as in the absence of Mg iron is not absorbed by plants
ManganeseNewDead yellowish tissue between leaf nerves
MolybdenumOldBrown edges, inhibited flowering or yellow spots between leaf nerves
NitrogenOldStunned growth, leaves turn yellow and die off or slight reddening of leaves on occasions
PhosphorusOldDarker leaves or poor growth of roots/leaves
PotassiumOldAppearing of pin holes which may enlarge; Curled leaves and patches of yellow
SulfurNewLeaves turning yellow to die off
ZincOldYellowish areas between nerves, starting at leaf tips
CalciumNewDistorted leaf growth; Yellowish edges of leaves and twisted short roots

Any matching symptoms for your aquatic plants? It’s time to get some fertilizers for your plants!