Feeding Aquarium Plants

Micro and macro nutrients

Nutrients for the aquatic plants are divided into  two groups – macro- or micronutrients. Plants need more macronutrients than micro but both are important as well. Macro include: hydrogen, calcium, carbon, ,, nitrogen, oxygen, magnesium phosphorus, sulfur, and potassium.

Plants require a number of organic and mineral nutrients in order to maintain steady growth and good general health. Every nutrient is needed for optimal growth, even if just minimal value of it is required. Feeding aquarium plants you can compare it to the diet, but for the plants. You don’t want your plants to have health problems or that something will limit their growth. It is good to consider a purchase of good aquarium fertilizers, and substrate. You can deliver nutrients in many different ways(methods).

Micronutrients are needed only in trace amounts. Micro includemolybdenum, boron, copper, manganese,  chlorine, zinc, iron, and nickel .

You don’t have to worry about oxygen and hydrogen(there is more than enough). Other like calcium and nitrogen you can find in aquarium water. However in very soft water, there might be not enough calcium. When your plants are growing well you may need to start providing them nitrogen, because it might be not enough of it from ammonia and nitrates. For sure if you would like to have underwater garden you will have to provide also carbon, magnesium, phosphorus, sulphur, and potassium for your aquarium plants.

Consider macronutriends as proteins in your diet, it will build you plants. Micronutrients are responsible for managment and control of whole ‘plant body’. Some micro you will find in the tap water, but those are used very fast so you will have to consider buying a good fertilizers. A good choice is: seachem fluorish, CSM+B, Tropica master grow, Pfertz micros, TNC trace elements.


Tap water quality and micronutrients level is depended on where you live. It is better to find out or check hardness KH/PH, ph, nitrates in the tap water(metal and toxicity as well but it is hard without professional stuff). That is also why we do regular water changes to keep these nutrients at good level for aquatic plants. It is usually best to use tap water (rather than reverse-osmosis or rainwater) at least partially as a source of nutrients in a planted aquarium. As long as you don’t want to go pro you may forget about RO filters and adding all elements by yourself. You can still have good quality high-tech aquarium using tap water.


‘While you are selecting suitable nutrient mixes, bear in mind that some fertilizers include other micronutrients that are not essential for aquatic plants and need not be added to the aquarium. Some terrestrial plants may require these nutrients for functions that are not present in aquatic plants, such as nitrogen fixation (obtaining nitrogen from the atmosphere). These nutrients include sodium, silicon, iodine, and cobalt. Aquatic plants do not need these nutrients.’

Nutrients uptake

In the aquarium, nutrients can be supplied to plants from a number of sources. Because plants take up nutrients both through their leaves and the roots, nutrients should be made available in the substrate and the water

Deficiencies and excesses

An excess or deficiency of one or more nutrients can cause problems to both fish and plants in the aquarium. Because plants have no control over the amounts of some of the nutrients they absorb (such as copper) excesses can cause fundamental problems within individual cells that in turn affect the entire plant.’ That is the main reason why a good nutrients balance is a key. It is hard to find ‘golden middle’ by just calculating it all on the paper. You must watch your plants and see how they react. Don’t add right away recommended amounts, start with something smaller and then after few weeks you will know what are you doing. Slow growth, yellow leaves, brown or black spots, cramp growth may are the sings of deficiencies.

Sometimes, a deficiency of one nutrient can be caused by an excess of another. In this instance, the nutrient present in excess “competes” with the second nutrient, preventing it from being absorbed by the plant and causing a deficiency.’

Plants as an indicator of good balance

Plants can also be a good indicator of deficiencies and excesses. I use always one or two fast growing plants in my planted tank set-up, like different hygrophilias. In this way I’m able to notice the problem long before it will affect slow growing plants. Fish might also be a good indicator. My clown louch and its colors tells me that water in my aquarium is very clean. If colors would fade it is a bad sign that something is wrong.Slow-growing plants have bigger storage for nutrients, just in case, that’s why they will be fine and if you will work fast deficiencies and excesses won’t touch them.

Sometimes plants will store too much nutrients because of the excess of it in the water or/and substrate. This nutrient build-up may be toxic for them. When there is too much iron for example all plants which have red color will be very red. Also, will fade much slower even if iron won’t be available for a while. When other green plants will start showing problems on their leaves – brown spots.


On the plants leaves may also occur chlorosis occurs, which is disability to produce normal amounts of chlorophyll due to a lack of nutrients. Chlorophyll is used for photosynthesis and lack of it prevents this vital process. This affects every aspect of a plant’s health. Many nutrients are used in the production and correct functioning of chlorophyll. Chlorosis can be used as a general indicator of nutrient problems in the aquarium.