Planted tanks for goldfish … it may sound like an impossible dream … but is it? This article will help you find a successful route to a planted tank for your goldfish (hopefully!) and take you through some of the issues you might encounter when setting up a planted tank for goldfish. We hope you’ll find some ideas to try out for your own set up.
So many people say it can’t be done; after all goldfish eat plants, they dig, they blunder about, they pull up plants, and they like cooler water whereas many aquatic plants are tropical. But goldfish really benefit from having live plants in their tanks, they are just as deserving of a nicely planted set-up as their tropical counterparts.
Goldfish enjoy the sensory experience of playing around with plants, swimming through them, hiding in them and of course snacking on them. It makes a more natural habitat for them and encourages natural behaviours. Goldfish are intelligent, busy, ‘doing’ fish; they really do benefit from an interesting environment with plenty of things to do.
So, planted tanks for goldfish? Of course it can be done; it just takes a little trial and error. This article is written from personal experience and my own opinions; other people will agree/disagree so use this as part of your research into finding the best planted set-up for you and your goldfish.
Expectations of planted tanks for goldfish
When designing your set-up be realistic in your expectations. Those amazing aquascapes in the magazines and websites are beautiful but are not likely to last against a tank of goldfish. Consider the maintenance of the tank; goldfish tanks need to be robust and easy to maintain. Goldfish make a mess, they eat a lot and they produce a lot of waste so their tanks need to be easy to clean. Robust plants are a better choice than delicate frondy ones. Consider too that their ancestors came from rivers; these would have had a gravelly bottom rather than a fine carpet of delicate grass-like plants.
I’ve found that the options have changed as the fish have got older and bigger. When they were babies I had much more of a range of plants in my tanks but as the fish have grown I’ve found that the range has reduced to a few stalwarts which have stood the test of time. If I wanted a Takashi Amano masterpiece I wouldn’t have goldfish, but that’s not to say they can’t have something that will look good and work with their nature.
At what point can I add plants?
If you are just starting out and have not yet set up your tank and added your fish it is a good idea to get the plants in first so they can establish their roots whilst you are doing your fishless cycle.
If your fish are in the tank already and you are looking for ideas to re-vamp their tank you may need to take extra measures to help keep the plants in place while they establish. It is a good idea to put some heavier stones or terracotta planting weights around the base of new plants in tanks which already have fish living in them. This will stop the fish from getting close to the roots when they are digging and help weigh down stems against being pulled up.
Do I go for stems, bunches or potted plants?
Plants come in a variety of ‘formats’; bunched, single stems, rooted in rockwool or in some cases attached to bogwood or terracotta sticks. If you do not yet have fish in your tank you have a greater choice of ‘formats’. For example you can buy stem plants, push them into the substrate and leave them to root while the tank cycles. Stem plants added to a tank which already has fish in it are very likely to get pulled up before they have a hope of rooting. If you have no fish then I would suggest stems as these are cheaper, but if you have fish already I would suggest going for rooted in rockwool as the established roots will help the plant hold onto the gravel.
What about substrate?
There are many commercial substrates available, however, I’ve personally only used soil and gravel so cannot comment from experience on other substrates – there is plenty of information available though so have a look through our recommended forums for more information on planting substrates
My personal suggestion for substrate in a planted goldfish tank is quartz gravel, small pea gravel (2-3mm) or a mix of the two. I find this makes it easier to keep the substrate clean. Goldfish produce a lot of waste and the substrate can get very dirty which can lead to pollution and health problems if it is not able to be properly vacuumed. I found that having a soil or other planting substrate under the gravel makes it harder to vacuum – the substrate gets all mixed up with the gravel and in my experience you end up with a muddy mess! Not forgetting the fact that goldfish dig and can quite easily dig up a planting substrate which again makes quite a mess.
Quartz gravel is fine enough for plants to root in without allowing the substrate to become compacted. Pea gravel comes in a variety of sizes, the smallest grade is about 2-3mm in diameter and this is ideal as it is also fine enough for plants to root in. Sand is another possibility but not one I’ve used myself. Sand can become quite compacted which makes it difficult for the roots to move around and grow as well as having the potential for anaerobic patches to develop if you’re not careful.
Which plants will work well in a planted tank for goldfish?
Goldfish cannot resist nibbling, snacking, pulling at plants, digging around them, and blundering through them. Plants need to be robust and able to withstand the fishes’ attentions. Very delicate frondy plants or those with small or fine leaves are not likely to last long. Floating plants also have limited success as the fish like to eat the roots, swiftly followed by the rest of the plant! Fast growing plants are a good choice as they have a better chance of keeping pace with the fishes’ attentions.
It will more than likely be a case of trial and error before you find the right plants for your particular goldfish. Some goldfish destroy certain plants while others leave those same plants well alone. I have used the following plants with varying degrees of success:
Giant vallis (Vallisneria gigantica): This does live up to its name so be warned! It can grow well over 3 feet long and benefits from a deeper tank. The leaves are broad and quite tough. They can grow quite fast but this is good news with goldfish! You can get smaller varieties of vallis such as V. americana, V. spiralis and V. tortifolia. These are a little more delicate due to their smaller size but are still mostly capable of withstanding goldfish. If it gets too long it can be trimmed by cutting the leaf at an angle. The tall plant in the background below is V. gigantica (the ‘model’ is the late, great, Fishie, he’s got a lot to answer for, he started me off on the fishkeeping road).
Amazon sword (Echinodorus amazonicus): These have large, tough leaves and can generally hold their own against most goldfish. There are a variety of species including A. bleheri and A. ocelot which are also suitable. You can get smaller dwarf swords such as Echinodorus tenellus, these are also good as they still have the same tough leaves. Amazon swords sometimes prefer warmer water to goldfish but it might be worth trying one or two and seeing how they get on.
Java fern (Microsorium pteropus): Goldfish are not meant to like the taste of these but this doesn’t stop them pulling at the leaves even if they don’t actually eat them. The plants are quite tough though and propagate quite happily. They are best grown attached to bogwood or terracotta sticks. An additional bonus of this is that you can easily take them out of the tank to clean around them. My fish dig vigorously in the ferns but so far have not damaged them. You can buy them already attached to bogwood/terracotta but if you want to make your own you can simply tie the plant on with some fishing line. They will take root and overgrow the fishing line so you won’t be able to see it.
Hygrophila: There are various types; H. polysperma being one of the most common and popular. Hygrophila is a stem plant; it grows quite quickly and is quite happy in the water conditions goldfish prefer. I’ve had mixed results with these, some have done well and been left alone for months only to be eaten almost overnight when the fish suddenly take a fancy to them. Probably a trial and error plant. There is a very pretty variegated version too, H. rosanervig, which I’ve also had success with.
Ludwigia: This comes in different colours and has reasonably robust leaves and stems. It grows in a rather attractive way as it sort of ‘spirals’ around the tank in a bid to keep all its leaves exposed to light. The red version is attractive but does require decent lighting to maintain the red colour. Another mixed result plant so again, trial and error is the key.
Cryptocorynes: There are a huge number of different types of “crypts”; in my experience the larger ones such as C. wendtii or C. becketii seem to fare the best. If you can find one, C. usteriana has stood the test of time for many years against my fish. This is a large crypt, growing to approximately 60cm in height with strong stems and large leaves. My own specimen is at least five years old now!
“Pond weed” (Elodea/Egeria densa, Elodea crispa): Densa has straighter leaves and is quite dense in growth while crispa is the curly leaved one most commonly thought of as pondweed. They do root but I prefer to keep them bunched in strips of sponge and lead. These are what I call ‘sacrificial’ plants – they will almost undoubtedly get eaten but are cheap, fast growing and keep the fishes’ attention away from other plants. Keeping them bunched makes it easy to tidy them up when the fish have pulled at them; just take the bunch out, rearrange and replace stray bits and then push it back into the gravel. This is a good plant for removing nitrates. Personally I prefer E. densa as I think it looks rather more attractive.
Hornwort (Ceratophyllum demersum): This is one of my personal favourites. It doesn’t root so can be bunched or left floating. I prefer to bunch mine, the fish prefer to pull it up and have it float! Like elodea it is cheap, fast growing and keeps the fish away from other plants. Another good plant for removing nitrates, it has the added bonus of giving off an algaecide to help protect it from being smothered.
Moss balls (Chladophora aegagropila): Some goldfish will shred these to pieces, others don’t bother with them so another trial and error one. I like my fish to have them even if they shred them as they are great for removing nitrates. If you buy these online it’s a good idea to contact the seller first to check the size of ‘large’ ones. They will grow, given the chance, although they grow quite slowly. I have one I’ve had for a while which I’ve ‘hidden’ at the end of the tank the fish don’t go to very often. It’s a good eight inches across and the fish have been threatened with terrible sanctions if they so much as look at it the wrong way! Others are more ‘moss rugs’ now, goldfish can be quite artistic on the home decor.
Onion plant (Crinum thaianum): Onion plants can grow large but can be cut back to keep them in check if need be. They have long leaves similar to giant vallis which can look rather attractive going along the top of the water. They have bulbs which root from the bottom. I found them a little tricky to get them to establish as they are a little buoyant but a bit of planting sponge wrapped loosely round the top of the bulb with some planting lead loosely wrapped round that helps hold them down until they get a grip with their roots. They should be planted with just their roots under the substrate, keep the bulb above it otherwise it rots.
Algae: Strange as it might sound considering the lengths many go to to keep algae out of their tanks, algae can have its uses. I’m only referring to the type that grows on glass though, when it gets a hold on your plants that’s something that will need dealing with to avoid damage to the plants. I’ve taken to letting algae grow all over the back glass of my tanks, it takes up nitrates and provides another source of nibbles for the fish. Micro-organisms grow on it too which the fish also like to nibble at. It’s quite handy in fry tanks too as an additional source of food.
How best to plant them?
The only plants I keep bunched are elodea and hornwort. If anything else comes wrapped in sponge and lead strips remove these and separate out the plants. Stems should be individually pushed into the gravel. If you have bought potted and/or rooted plants you should remove the rockwool and plastic pot then push the roots gently into the gravel. Vallis needs to be planted so the top of the roots are level with the top of the gravel, do not cover the stems with gravel. You may need to protect the area around the roots if you have fish in the tank.
What about layout?
Taller plants should be at the back and sides of the tank, shorter ones in the foreground. Don’t forget to leave an area of clear water for swimming and a clear area of gravel where you feed the fish. There is no point having plants directly under the area you drop their food in as they will damage the plants while looking for their food. I like to have one end more heavily planted than the other, my fish have a preferred area of the tank for sleeping so I put lots of plants around that area – this helps them feel secure when resting. Find out how the currents work in your tank with the filter and any airstones you have – make sure the plants do not restrict flow too much as this will lead to areas where debris collects.
What about lighting?
I am by no means an expert on lighting but there is a good article on lighting on fish keeping.co.uk. My own lights are flora-glo and sun-glo fluorescent tubes which are sufficient for my plants. My tanks will take four tubes but I only use two as I’ve found four can heat the water up a little too much for goldfish.
Do I need to use fertilisers?
Certain plants do require additional nutrients at root level; swords and cryptocorynes in particular. You can buy root tabs which are little tablets of fertiliser that you push into the gravel underneath the roots. There are also plenty of liquid fertilisers on the market. I use root tabs but don’t use liquid fertilisers on a regular basis. I do sometimes add some liquid fertilisers, I ‘mix and match’ between a weekly one and a daily one. If you decide to supplement with fertilisers I’d suggest choosing ones which do not include nitrate and phosphate. The nitrogen cycle produces nitrate as its end result anyway so there will always be some being generated in the tank. Phosphates are sometimes in tap water so test yours and see what the results are. Generally though I’ve not noticed a lack of growth from not adding phosphate.
What maintenance will I need to do?
If you are fortunate your plants may need pruning occasionally. Stem plants such as elodea, hornwort, hygrophila and ludwigia can be cut and the cut ends replanted or rebunched to make new plants. The fish will undoubtedly pull up some plants so these will need to replanted or rebunched. I do mine on a weekly basis when I do my water change. You will need to replace elodea and hornwort every now and then as they become shorter and barer of leaves …
Bunching in sponge and lead strips is simply a matter of gathering some stems together, wrapping them in wet sponge (most bought as bunches will come with sponge around them) then wrapping some planting lead around the sponge to hold it in place and weigh the bunch down in the water. It is worth checking the sponges regularly as I’ve found some of mine have developed anaerobic patches in the sponge. If the sponge smells ‘eggy’ it has developed anaerobic bacteria and needs replacing. If this is the case, remove any rotting plant matter from the end of the plants by breaking off any brown/black sections then rebunch as required. I tend to use two strips of planting lead as one often isn’t enough to keep the plants from floating, especially when the fish are digging around them.
Small pieces of elodea and hornwort can be left to float until they get big enough to include in a bunch.
Any other ideas?
As well as planting directly into the gravel you can set-up containers such as terracotta plant pots with planting substrate and a gravel top layer to put your plants in. These can be arranged on the bottom of the tank and removed for cleaning or if you need to catch the fish for any reason (trying to catch a fish in a heavily planted tank can be quite a mission!). You can also use plastic containers as plant pots but these must be food grade so they do not leach anything into the water.
Some plants can be attached to bogwood or terracotta sticks, for example java fern and anubias. Again, this means you can remove the plant easily to clean around it.
Plants such as elodea can be kept in a tub in the garden during the warmer months of the year. Kept in a sunny spot it will grow quite nicely, especially if you add some of your tank water from your weekly water change as the nitrates will act as food for the elodea. This will help some straggly bits recover, as well as providing a source of replacement plants for when the ones in the tank get a little threadbare.
But won’t the goldfish eat all my plants?
Goldfish are generally good eaters and need to be kept well fed. Many people are warned of the dangers of over-feeding and in their attempts not to they actually end up under-feeding. Feeding lightly is advocated more for the purposes of keeping the waste products to a minimum and so keeping the water quality under control in aquaria that are often too small, overstocked and under-filtered. With a correctly sized, correctly stocked and correctly filtered tank this should not be a concern. Feed your fish well and they may be less inclined to munch on your plants.
If you are going on holiday it is possible to leave your fish unfed for up to two weeks if they have been well-fed beforehand. However, in the absence of their daily rations they will turn to their plants when they want a snack. If you are going on holiday it is a good idea to buy a few extra bunches of elodea and put them in the tank before you go. This should help minimise damage to other plants. If the fish are nibbling at the plants more you may find the filter becomes clogged more quickly; make sure the filter is cleaned before you go on holiday and then give it a clean when you come home.
It’s not possible to prevent your fish from eating your plants at all, after all, it’s part of their nature and part of the reason for having plants with goldfish is so that they can add them to their diet.
Resorting to fakery …
As my fish have got bigger, and the number of species that can stand up to them has declined, I’ve found it can be helpful to mix fake plants in with the real ones. The fake ones soon get a slight covering of algae which the fish will also nibble at and can help ‘take the heat off’ the real plants. Mixing them up together will also make it slightly more of a challenge for the fish to get at the real plants which might also help. There are quite a few different brands of fake plant and it can be tricky to find ones for larger tanks, but I have some from the Marina Naturals range which are silk and plastic and come in ‘L’ and ‘XL’ sizes; these are about 38-45cm tall depending on style. I’ve also used plastic plants from a company called Velda. These are intended for ponds, including koi ponds, and are very robust. The elodea version is fairly convincing and the plastic is nice and soft so they waft about nicely. They are 100cm tall so work well in deeper tanks and look nice flowing along the surface.
Please don’t think you can only have fake plants though, there are still plenty of options for keeping live plants with larger goldfish! The photo below shows live and fake plants mixed together in a goldfish tank.
A final note …
The most important thing is that you and your fish enjoy your tank. If something doesn’t work for you don’t be down-hearted, something else will work just fine. Goldfish tanks can be a bit of a permanent work in progress but this is part of the joys of keeping these hugely entertaining and big-personality fish.
Author: Suzanne Constance
This article was originally written for fishkeeping.co.uk. As the author of the original article I retain the copyright so am reproducing it here, albeit with a few minor tweaks.
More pictures will be added soon so watch this space for updates.