Goldfish and Plants: The Low-Tech Approach

Keeping a planted tank has many advantages. Plants consume ammonia, nitrite and nitrate and they are part of the biofiltration in your tank. Healthy growing plants produce oxygen. And many of us find planted tanks appealing.

Goldfish also like planted tanks. To most of these omnivorous piggies, plants mean food. Before you know it your beautiful green plant may soon look something like a winter tree



Be realistic
A goldfish tank will be first and foremost a goldfish tank. You may not be able to keep a perfect aquascaped tank with goldfish in it. Not only to they eat plants, they uproot them quite easily and when they spawn, plants get easily torn apart. But with some planning and a bit of trial and error you should be able to keep a nice green tank with your goldfish.

Be tricky, very tricky
Since the little (or big rascals) in your aquarium like to eat your plants, you have to try to outsmart them. Here are some tips

Find plants they do not like. (see below)
Use plants that float - hey they cannot be uprooted
Use plants that can be tied down - you're one up on the rascals with this one
Find alternative ways to pot your rooted plants. Use clay pots with substrate. Add a mesh to help keep the plants in place
Plant several at a time. It may just confuse them a little

Be picky, very picky
Choose your plants with care. Try find plants that goldfish do not like to eat, that you can tie down rather than plant in the gravel or that do not tear that easily. Pick plants that grow fast. And don't give up. Goldfish ate the two first plants I tried but hey I just got smarter and now they live with plants and we are all happy.

Plants to begin with (ordered according to success possibility-starting with the best)

Java Fern (Microsorum pteropus) A very hardy plant, with low light requirement. Goldfish tend not to like the taste of this one. It can be tied to rocks, decorations is therefore not easily uprooted.
Anubias (Several varieties) Again a hardy plant with low light requirements. It has thick leaves and goldfish leave it alone. Best when tied down to decorations.
Java Moss (Vesicularia dubyana) Java Moss is a hardy plant with low light requirements. Goldfish are not likely to eat it. But they may tear it up during spawning. Because of this it can make your tank quite a mess and have moss fragments slow down your filter. On the other hand when my goldfish spawn I like to provide them with Java Moss as spawning material.
Hornwort (Ceratophyllum demersum) A plant that can float or be placed in the gravel if you prefer. It is hardy and usually escapes goldfish jaws. Mine have kept pace with goldfish grazing the last three years. I like this plant. It provides cover and it is a good nitrate consumer. If I plant it in the gravel and if (or when ) it gets pulled out I do not have to rush to replant it. It likes to float and it gets good light at the top of the tank.
Crypts and Swords (Echinodorus species) Crypt and swords are rootfeeders. They require a good and nutrient filled substrate. They would not like to be uprooted nor have their roots exposed. For that reason they do not always make the best choices but if you have goldfish that are not too pushy try them. They are very beautiful, and will do well with moderate light levels (at least 2.5 per gallon). While my goldfish are smaller I have had both plants.
Vallisneria (Vallisneria species) produce runners and it gets part of its nutrients from the water and part from roots so it requires a substrate. It is hardy and with low requirements. While my goldfish uproot this plant often it does well if I keep replanting it.
Hygrophilas (different varieties) and Watersprite (Ceratopteris thalictroides) These are stemplants and relatively hardy. However goldfish do tend to like to snack on their rather soft leaves. I tend to find them 'cut down' a bit if I leave the goldfish without food for a couple of days. But if you have luck with ones above you may want to try these next. Both tend to like better lighting than low, though. Watersprite has the advantage that it does well floating if it is uprooted.
Anacharis (Egeria Densa sometimes called Elodea Densa) Is a common pond plant. It can float or be planted in the gravel. It is good nice colour. People have varied success with it. Some goldfish tend to be particularly fond of anacharis. My goldfish leave them pretty much alone. However the plants tend to prefer cooler temperature and is often hard to keep in warmer aquariums.
Duckweed (Lemna minor) A tiny floating plant that really does grow like a weed if given the chance. In a goldfish aquarium it is rarely given the chance. My goldfish treat these as snack. They have the advantage of providing cover (if they are allowed to grow) and they are good nutrient absorbers without many high requirements. However they tend to like low surface movement and if the you have a lot of filter power these tiny things smay be drawn into the filter.
Be a gardener
Plants are living things. They have basic needs and you need to provide these needs.

fluorescent lighting - the brighter the better - (aim for at least 2 watts per gallon - for less demanding plants, towards 4 watts per gallon for more demanding plants).
heat - most plants are tropical plants and require warmer water. So if you keep your goldies fairly cold (low 70s) you are limited in plant choices. Egeria does seem to like colder water.
other nutrients
CO2 - Adding CO2 is not necessary in a goldfish tank. I do not aim at a very high tech tank and goldfish make plenty of CO2 as a part of their normal respiration. I do not add liquid carbon (Seachem’s Flourish Excel) to all my planted tanks.
Fertilizers. There are many fertilizers out on the market that allow us to add micronutrients (minerals) that plants need. In my experience they have to be used with caution. If you add too much (especially in a low light tank) you may see algae growth. One wonderful thing about goldfish is that they are such excellent fertilizers themselves.
substrate. Some plants are primarily root feeders and require a substrate – either plain washed gravel or a special plant substrate like laterite or Flourite. But using substrate in goldfish tank is difficult. Goldfish like to look for food in the substrate - they often move rocks around or take them in their mouths to try them out. However if you place your rootfeeders in clay pots you may be able to keep some. You can cover the top layer of the pot with very small gravel and even use a plastic mesh to help keep the plant from being uprooted.


Be smart
Quarantine - it may be prudent to quarantine your plants by having them in a quarantine tank for at least two weeks. Some plants will not like the process of being replanted again(such as crypts or swords). You may also subject your plants to chemical baths that may kill dangerous pathogens.
Potassium Permanganate (PP) is a product I often used to treat plants. You can bathe your plants for 15 minutes in a 10mg/l solution of PP. You can also use a copper product called Had-a-Snail to remove snails and pathogens sensitive to copper. Remember to rinse the plants thouroghly after bathing them in chemicals.
When goldfish get sick, plants may suffer from the treatments you use. Therefore you should add plants to Quarantine or hospital tanks

So that is all there is to it. You just have to be a realistic, tricky, picky, smart gardener. And may all your aquariums be green.

© TheGab

Rick