Goldfish and Aquarium Plants

Goldfish are avid plant eaters but there are aquatic plants that can resist their attacks.

Introduction to Aquarium Plants for Goldfish

Goldfish and plants aren't a good combination, as being omnivorous they consider aquatic aquarium plants as food that help fill their dietary requirements. It is very frustrating planting up an aquarium only to find a few stems left the next morning.

If Goldfish are fed lightly, during spring and autumn you will find them more likely to attack aquarium plants.

Plant eating can be quite fickle; one group of Goldfish will devour certain plants, while others will completely ignore them, duckweed is a prime example.

There are plants that I found to be resistant to their attacks through trial and error when I was hiring aquariums.

Last Updated: 11-14-2024 by Grant Lord.

Plant Selection Criteria

Plants have different uses in the aquarium.

Some are used to hide filter equipment in the aquarium, others grow quickly, some are very good at nutrient absorption (nitrates), and others are used purely for ascetic reasons.

Plants can be divided into background, foreground or visual interest plants.  There are also plants that are suitable as food to fill dietary needs.

Background Plants

Vallisneria (Eelgrass, tape grass)

One of the more popular aquarium plants, these tall fast growing plants are used in the background as they are useful for hiding filter plumbing.

The leaves are tough and strong, so they are not normally eaten by herbivorous fish.  This plant is easy to propagate using runners, which are prolific if the substrate provides sufficient food.

In the recent past there has been confusion regarding what species of Vallisneria exist, and what varieties come under each species.

In 1982 two independent botanists came to the same conclusion; there are only two species:

• V.Americana and
• V.Spiralis.  The term spiralis refers to the long spiraling stalk of the female flower that reaches upwards to the water surface, not the shape of the leaves.

Both species have two varieties, one that grows its leaves in a corkscrew shape, and the other in flat ribbon like leaves.  There are several hybrids and variants available.

The most common varieties used are:

• Corkscrew Vallisneria.  The leaves of these varieties grow in the form of a corkscrew, and grow 30-50cm (12-20 inches) in length.  Some newer dwarf varieties only grow 15cm (6") tall.
• Giant Vallisneria.  The leaves can grow 180cm (6 foot) long, so this variety is more suited to very tall aquariums or deep ponds.
• V.Americana or V.Spiralis with flat ribbon like leaves hence the name tape grass. The most commonly used form with the leaves reaching between 90-120cm (3-4 feet) long.

Vallisneria has a pH tolerance of 6-9.5.  Temperature range 20-28^oC (68-82^oF).

Hygrophila Difformis (Water Wisteria)

Suitable as a background plant for shorter aquariums.

Fast growth helps prevent algae because the plant absorbs a large amount of nutrients from the water.  It tolerates lower light levels, but higher light conditions leads to enormous growth rates.

A shortage of micro-nutrients leads to pale leaves, which may be an indication that the aquarium needs fertilizer. It has a pH tolerance of 5-9.

Temperature range 18-30^oC (64-86^oF).

Foreground Plants

Blue Hygrophila

This plant is mainly used as a foreground plant.  It is a bog plant that can adapt to complete immersion in water.  It is sold as a cutting. It is a fast growing plant in conditions of good light and an algae-free environment.

Under ideal conditions, it can grow to the top of the aquarium. The leaves are often chewed by goldfish during spring and autumn or if they are very hungry. It tolerates wide pH and temperature ranges.

Plants for Visual Interest

Ludwigia Arcuata

Used for creating interest.  It requires a relatively large amount of light before forming a red stem and red leaves.  It thrives best in slightly acidic water.

The most decorative effect can be achieved by planting it in groups. 

PH range 5.5-8.0, Temperature range 20-28^oC (68-82^oF).

Red Hygrophila

Again used for creating interest.  This plant comes from South America and is a marsh plant.

It is slow growing and needs algae-free conditions to prosper.  It is hard to propagate from a cutting, has a soft delicate stem easily bruised, and can easily rot back even though it has been planted with a rooting node.

It needs good light.  The cuttings start green on top and red underneath, but new leaves are ruby red and very decorative.

PH range 5.0-8.0, Temperature range 22-26^oC (72-79^oF).

Red Bacopa

Again used for creating interest.  The plant comes from Southern USA and Central America. Its leaves are quite fragrant.  Cultivation is done by rooting stem cuttings.  It requires good light and an algae-free environment.

Goldfish will generally not chew on this plant.  The leaves, completely green initially, get quite a red tinge to the underside.

Its tolerance levels for pH and temperature are well within the levels experienced in the aquarium.

Plants Suitable As Goldfish Food

If you want to give your goldfish a treat or need to increase green matter in their diet, use Elodea Crispa or Elodea Canadensis, both also known as oxygen weed. They love it!

It will grow when free floating but it grows more vigorously if it is rooted in substrate.

Tolerates lower water temperatures 7-24^oC (45-75^oF).

Conclusion

There is quite a selection of plants that will resist hungry Goldfish, it is just a matter of deciding what you want to use the plant for; hiding unsightly equipment, aesthetics or functional benefits.

Keep in mind the Goldfish variety you own or are planning to keep.  Some of the fancy varieties such as Celestials or Water Bubble Eyes and Moors will have difficulty navigating a heavily planted aquarium. 

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