Helping Aquarium Plants Grow

Helping Aquarium Plants GrowFor a freshwater aquarium, plants are a great addition that not only enhance the look of a tank but also bring benefit to the inhabitants living there. By giving plants the proper ingredients, it will help them to grow lush, vibrant and healthy. Plants will grow in a variety of conditions and are sensitive to any subtle changes in the water. They will in turn grow accordingly to these changes.

As we all know light is the main building block to help plants grow. It serves the most important function of photosynthesis but without nutrients, plants become stunted and cannot thrive. A balance between your tank light and nutrients is essential.

Trouble maintaining your aquarium plants?

Take a look below for some obvious and some not so obvious potential issues you could be experiencing now.


Vital if you want any plants to grow. It might seem basic however getting it right can take a few goes. The intensity and spectrum of the light are the two main factors that will determine how your plants will grow. Plants grow in a variety of light spectrums. Any spectrum between 3200K right up to 12000K will be beneficial for plants. 5200K – 10000k is the preferred spectrum to help plants achieve optimum growth. Intensity/brightness of a light is measured in LUX  and the amount of light is measured in Lumens. LUX is the focal point of light – how bright this light is reflected off a given object, while Lumens is how much power is being produced by the light. The higher this number the better the effect on plant growth. Quality of light is determined by what type of light you use.

Is the light you are using penetrating deep enough for your ground cover to grow well enough? For a deeper and wider tank, more light will be needed than say a shallow Nano tank. Water reduces the intensity of the light as it travels through it.

The table below is a simple example of the four main lighting types and their strengths. For instance a high strength light is needed to grow carpet plants. Some lights come in multitude of strengths.

T8 Low Strength
T5 Low Strength High Strength
Metal Halide High Strength
LED Low strength High Strength

Always ask your aquarium retailer if in doubt about what lighting to use as they will know. All of these come in a vast array of sizes, strengths and manufacturing quality. Much like bulbs you purchase for your home, you make a decision of how much you are willing to outlay and therefore know how long till replacement. There are rules of thumb for lighting but I am staying away from specifics here. Plants love light, the more you give them the happier they will be. Controlling your light hours will also manage your algae growth. If algae is growing too quickly then reduce your light time by ½ an hour to 1 hour. About 8 – 14 hours is needed each day for plants dependent on the light source used. Algae growing on the leaves of a plant will reduce light absorption as the surface area will be diminished. This can lead to deterioration. Always keep your aquarium out of direct sunlight as any excess light will encourage algae to multiple more rapidly.

Sparse growth can usually be treated with improving quality, strength, adding more lights, duration or a combination of them. Give plants room to grow. Once planted they are going to need space. If too confined, leaves will become brown and die off as light will not be able to reach them. Space plants out so each leaf receives light, making  sure overshadowing does not occur. Certain plants like Ferns, Anubias and Mosses can be kept in a bit of shade as they are not as light hungry. This helps the slower growing Anubias plants as more light will produce more algae on the leaves. The majority of plants however cannot get enough light.

Lighting these days is getting better and better. More focus is put on planted tanks with aquascaping taking off. This is perfect if you are primarily focused on a planted tank setup. High tech setups are not necessary to achieve a beautifully planted aquarium. Don’t be disheartened if you are having trouble growing carpet plants. If poor lighting is on your aquarium then it’s the equipment that is letting you down not the user. If you don’t have the money to upgrade and have a smaller light on a bigger tank then you can always move your low light plants to the edges and keep the more light hungry plants in the centre.


Each brand of fertilizer contains different amounts of nutrients and minerals. Subtle differences can make a big impact. When switching brands, you may find different plants in your tank reacting better than others. pH plays a major role in what minerals get absorbed by plants. A slightly acidic pH will absorb the widest range of minerals available. This is just chemistry and the way minerals respond at that level.

Liquid fertilizer is extremely efficient at maintaining growth. When introducing a liquid fertilizer, there is enough nutrients available for them to grow. A Potassium/Iron fertilizer is the basis of what needs to be added to an aquarium as these nutrients are not present in large enough quantities for plant growth. When adding a potassium/iron fertilizer, growth of a wide range of plants can be achieved. If you are having problems with this then it would probably be the light you are using or the pH. Keep it simple. Be mindful that the directions on packaged labels should be used as a guide as they would be for an average setup of plants as it is easy to over or under dose your plants. It is worth taking the time to work out your personal dosage amounts. Not just to save you from replacing products sooner than needed, but to give your plants the right balance in order for them to flourish. This can also help to reduce algae, by giving your plants more fertilizer, it will encourage them to grow and absorb more nutrients from the water. Using test kits will make it easier to see what is going on with the nutrients in the water.

Floating plants or any attached to aquarium features will also require a liquid fertilizer as their roots do not have access to the substrate. Java Fern is an example of a plant, where the leaves absorb the nutrients required to grow and not the roots.

Plants do not need to be rooted in the substrate in order to grow but it does look a whole lot better. By keeping plants uniformly in the substrate, it will help them to all grow in the same direction. Substrate fertilizer does help in maintaining strong healthy growth especially in ground cover plants. If you don’t have a fertilized substrate that’s ok too. You may not be able to grow a few of the specific plants like Cuba HC or Glossostigma, but you can still have a tank full of flourishing plants. Another plus about substrate fertilizer is most nutrients are absorbed through the plant roots, thus avoiding to dose as much liquid fertilizer which help in reducing algae growth.

In order to maximize nutrients reaching all plants in the aquarium, tank flow must be managed. Nutrient balanced plants living in peak conditions ensure more oxygenation which in turn assists nitrifying bacteria.


Arguably one of the best additives for plants is the addition of CO2. Plants are around 45% carbon. This accelerates growth of all plants with some plants unable to grow well without it. CO2 only needs injecting throughout the day as CO2 is absorbed while plants are consuming light. Surface agitation reduces CO2 in the water because of the gas exchange where air and water meet. This exchange releases CO2 from the water leaving less for your plants. For heavily planted tanks, less agitation is ok as the plants are producing a lot of oxygen. But for a non CO2 set up don’t limit the surface agitation as this can then be fatal for fish, plus the amount of carbon available in the water is minimal. Obviously plants will still grow healthy without CO2, however you will find most lush vibrant tanks will be utilizing this booster even if only sporadically. Ok so no CO2. Slower growth, that’s not so bad. With CO2 there is a lot more gardening to do each week! It becomes a consistent ritual you will have to keep up as overgrowth of certain plants will consume most of the light, leaving others underneath to quickly die off. Conversely, this information may be used to your advantage eg. slower growth of a plant. CO2 will work with all lighting although the more intense the light, the more effective CO2 will be absorbed by the plants. An intense light will ensure your plants give off more oxygen.


Type of fish and the amount of fish will also have an effect on your plants. Plants enjoy different amounts of nitrates, phosphates and potassium. * Different combinations of fish will produce different results for your plants, just like some people need to eat more iron than others. Usually there will be enough waste from the fish and food to supply nitrates and phosphates to the water but if you have minimal fish and a lot of plants then you may need to add a supplement to be certain your plants get enough of these. Larger more aggressive fish will limit the types of plants you can use. Cichlids are a good example of this. Always feed your fish everyday. Even though some plants like Anubias are tough, fish teeth will still bite through the leaves.


Water parameters play a vital role in the growth of your plants. As you know plants come from all over the world, varying greatly in pH, Temperature, etc. These differences have an effect on what each plants ideal conditions are. Keeping plants from the same area will keep things easier. Most plants do well in softer slightly acidic water and by keeping plants in this range, it will make it easier when housing a majority of plants. Plants can handle a wide range of water parameters, however maybe not growing to their fullest capacity. This may have an effect on leaf shape, colour, growth proportion and regrowth.

When introducing plants into a new tank, plants can go so far as too appear dying. Leaves may die off but the plant roots are the best indication of plant status. Often with patience during this ugly phase you will get stronger plant growth as the plant has completely adapted to its new environment. This too can occur during big water changes, or introducing snack happy fish.

Some other points to take into account

Each plant is individual and unique and will have its own endurance level. You will lose plants like fish even if everything is done to spec.

When planting your plants in the substrate be sure to only plant up to the top of the roots. This will prevent the rhizome or the base of the plant from rotting away. In saying that, this rule is not set in stone because if you do bury part of it, the plant will still grow and nothing will happen. Again it comes down to the individual plant. It is best to try and avoid this to give your plant the best survival rate.

When growing vegetables it is known that some types of vegetables grow better next to others. While this has not been tested with aquarium plants, you may find some combinations of plants just don’t work well when planted together.

Let plants grow. Allow them time to develop. By looking at them each day you don’t notice the changes taking place. Adjusting the water and fertilizer, moving them around trying to make sure they are in the best possible position. Let them be and don’t disturb them. This will help them to establish quicker and you will have better results.

Colour – plants receiving enough nutrients will be rich in colour.

Holes in leaves – Not enough nutrients or light.

Stunted growth – Not enough potassium, nitrates or light

Slow growth – Not enough Light, water parameters

Small leaves – Not enough nitrates

Long growth – Not enough light

Compact growth – Too much light

Algae – Too much light, too much fertilizer, not enough fertilizer, ambient light

Narrow leaves – pH, hardness, light spectrum

Wide leaves – pH, hardness, light spectrum

Start out simple. If you already have a few established plants in your aquarium, you are well under way to achieving a successful planted tank. Add a few more here and there to see how they go. If one doesn’t like the conditions you have, then simply find ones that will suit. Over time you will gain more experience with plants. When you see pictures on the internet of perfectly aquascaped tanks, the people who create them didn’t get there overnight. Play around to see what works and what doesn’t. In the end you will acquire more knowledge in this area, thus improving the health and well being of your fish in the process.