The benefits of a planted aquarium include:
- Water oxygenation – live plants absorb carbon dioxide and produce oxygen (when your tank is illuminated)
- Aded filtration – they absorb ammonia, nitrates and phosphates and contribute to maintaining a balanced water chemistry
- They serve as an extra site for the colonisation by beneficial bacteria
- They provide natural shelters for fish – reducing stress and supporting natural behaviour
- They stem algae growth by directly competing with algae for the intake of essential nutrients and absorption of light
- They look great!
Plants and lighting
Plants require illumination in order to thrive. It is not essential to leave an aquatic light on for more than 12 hours; in fact this is likely to favour the growth of algae rather than plant growth. To keep your aquarium plants healthy, the light and CO2 must be balanced.
- If the light is very intense and there isn’t a corresponding larger amount of CO2, the light can harm your aquarium plants
- Too much CO2 without a corresponding amount of light will affect your aquarium plants ability to photosynthesize, and can also harm your fish
- A balanced tank will have more plants than fish.
Symptoms of insufficient light:
- Leaves can be pale green to yellowish and their stems are weak
- Stem plants have few leaves and long internodes
- Growth near the light is vigorous and the lower portion of the stem is bare.
Carbon Dioxide CO2
Plants need CO2 to live. CO2 is naturally produced in your aquarium environment through the respirations of fish and the breaking down of organic material.
Carbon levels should run between 5 - 15mg / L, excess levels can harm your fish, but aerating the water (increasing the surface turbulence) can quickly cause the CO2 level in your tank to dissipate. CO2 diffusers or injectors promote plant growth.This can produce wonderful results when balanced with sufficient lighting and necessary nutrients.
Even plants that would survive without any additional CO2 can start growing much more rapidly when they receive extra CO2. This is a balancing act between your pH and KH (carbonated hardness) levels and you should monitor your tank and fish behaviour carefully. CO2 should only be added to an aquarium to promote plant growth once optimum fertilising and lighting regimes are in place. CO2 works very well but will not provide significant benefits unless these basic plant requirements are also met.
Advantages of CO2 injection:
- Creates optimal plant growth
- Provides the most essential and available carbon source for plants
- Excellent method of lowering the pH in aquariums.
If there is a deficiency of CO2 the aquarium plants stay small and grow slowly.
Planting your aquarium
Before planting your aquarium:
- Make a rough sketch of how you would like your tank to look
- Choose plants to populate these 3 categories:
Foreground plants – these plants are small and low growing
Middle ground plants – these are medium sized and can be used to block unsightly stems from your background plants
Background plants – these are your tall plants that can be used to hide your aquarium equipment such as heaters or filters
- There are also these to consider:
Bunch plants – these are usually middle ground or background species that look good in groups
Specimen plants – these are usually large, decorative species that are planted singularly in the middle ground or background
Contrast plants – these plants can be used as a contrast to the other plants in the tank such as red leafed plants
Floating plants – these plants require plenty of light and can be very prolific, make sure they don’t shade the plants underneath that require high light levels.
- Select a few species of each and buy in quantity rather than many different species with 1 or 2 of each
- Add all your plants at once as these will directly compete with the establishment of algae
- Always remove the devices that hold plants together when planting
- Never bury the crown of the plant
- Be aware of their maximum size and provide enough space to allow for growth
- Remove any dead or decaying leaves immediately.
Different plants have different needs, while some grow in substrate or pots, others grow attached to driftwood or rocks.
Ideally substrate should be 1.5 to 3.0mm in size and the depth required will vary from 3cm to 8cm. An average of 6cm should be suitable for most species, although the Echinodorus requires a depth of 8cm.
The substrate should be a material that does not affect the pH of your water. It is better to use natural materials rather than synthetic such as epoxy coated or coloured ceramics.
Fertilisation / nutrition
There are various fertilisers on the market for enhancing aquarium plant growth, follow the instructions on the labels and make sure it is an aquatic safe fertiliser. These fertilisers are free of phosphates and nitrates. The most common types are solid / granular (root absorption) or liquid (leaf absorption).
Not all liquid plant foods are complete fertilisers. Some are meant as trace nutrient supplements. Check the label.
Healthy plant leaves should be green and shiny with new buds appearing. If your plants are pale and white this is a sign that indicates poor nutrition.
Aquatic plants will flourish with ongoing care and may even become large enough to start growing outside of your tank! Thinning and pruning is important! You don’t want the vigorousness of your plants to shade your aquarium and increase your algae growth.
Practice this ongoing care for a stunning plant display:
- Remove any decaying or yellowing leaves
- Remove any dying roots – these appear limp and brown
- Thin and prune as necessary
- Add fertiliser as directed on the packet
- Check your aquarium light and replace bulbs as per the manufacturers recommendations.
Plant problems and solutions
Besides algae infestations, plants can suffer other ailments, especially when the water conditions are not favourable. Water with incorrect properties can cause as much or more damage to a plant than nutrient deficiency. If plants begin to wane (i.e. prematurely yellow, lose leaves, and show leaf damage), first check that the water conditions (pH, KH, phosphates & nitrates) are in order. If they are, see the chart on the following page for help.
Lower leaf loss on plant stem
|Insufficient Lighting||Make sure the light is on long enough
Check the light bulb and change if necessary
Is your light strong enough for your plant's requirement?
|Small brown spots, developing into holes
|High nitrate content from lack of water changes||Make a series of moderate water changes|
|Small, irregular holes with sharp edges in otherwise seemingly healthy leaves||Snail feeding||Remove snails by hand, or use snail trap|
|Stunted growth, Premature die off||Carbon dioxide deficiency||Start fertilising with carbon fertilisation.|
- Tank set up
- Test kit with pH, ammonia, nitrite, nitrate & KH test strips
- Plant fertiliser
- CO2 diffuser (optional).