Aquarium Plants

A lush green and red underwater world for goldfish to explore, hide, rest and play can really make an aquarium stand out. The same is true for smelly rotten plants, but for totally different reasons.

Aquarium plants have the same needs as any other plant: somewhere to put their roots, nutrients for sustinence and growth, and carbon dioxide and light for photosynthesis.

Red and green plants in an aqaurium.


Substrate is the commonly used name for the sand that aquarium plants take root in. It needs to be coarse enough for water to circulate, and fine enough for the roots to take hold in. The optimum size is between 1mm and 3mm, and the optimum depth is between 5cm and 10cm.

Pea gravel and glass are no good for maintaining aquarium plants. There are commercially available substrates that are designed to promote healthy bacterial growth within it, and to provide trace elements that would be provided by water flow in a natural setting. The other advantage of commercial substrate is that is looks a lot nicer than sand or gravel.

Of course, there is nothing wrong with putting pea gravel or glass over a good substrate that might not look as nice.


Some plants will get all the nutrients they need from the substrate, but others will require feeding. As well as trace elements, plants also need nitrogen, phosphate and potassium. A good portion of this will come from goldfish faeces, but the amount of fish in the tank plus the cleaning regime will have an impact on how much of these compounds are in the water.

Again, commercial aquarium plant food is available and is often necessary to maintain healthy aquarium plants.

Carbon Dioxide

Plants need carbon dioxide to make sugar, which they turn into energy for growth, repair and reproduction.

There are various methods for introducing extra carbon dioxide into the water, ranging from the home-made to the professionally expensive.

It may seem counter-intuitive to dissolve carbon dioxide in the water that goldfish need to get oxygen from, but the two gasses are dissolved independently, and the amount of one does not effect the other.


It’s best to use flourescent light, as standard incandescent lights will heat the water and use far more electricity. For healthy plants, simply mimic natural summer time light. Leave it on for about 14 hours a day for the aquarium plants to get all they light they need.


Once the aquarium has been prepared for plants, the maintanence is fairly straighforward. Remove floating plants, dead or unhealthy looking leaves, and keep an eye on the goldfish for signs of disease.

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