Most hobbyists start keeping aquaria because of their interest in watching fish, not plants. However, with time one realizes that a natural looking setting, with live plants, is more appropriate than ceramic shipwrecks and bubbling divers. Aquatic plants are not only an ideal background to showcase your aquatic habitat, but they’re also good for fish. Plants improve water quality by allowing biological filtration, removing nitrates, and oxygenating the water. Fish in a well-planted tank are less stressed and more likely to breed. In addition, a successful “green thumb” can be a good source of revenue when surplus plants are sold. This article is a starting point for beginners who want to keep plants for the first time and others who may have been disappointed with their first attempt. Raising a healthy tank full of plants takes extra time and work so it is important to get off to the best possible start.
GETTING STARTED
The first thing to do is double-check your planned equipment. The first tank should be a small to medium sized one, such as a 60 to 100-liter tank. This size is best because maintenance is easier and the initial planting won’t cost as much. After the first tank has become well established, it’s plants can be used to start larger tanks. Choosing an overly large tank for the first attempt will just lead to frustration since most beginners underestimate the amount of work a large tank requires. Also, it’s important to avoid very deep tanks. I like my tanks to be no deeper than about 50 cm. You’ll end up doing a lot of stretching, when planting and pruning if your tank is too deep. It’s also a lot harder to decorate and light deeper tanks.
The gravel should be a medium to coarse sized gravel. I prefer a product sold by Sil-Silica called Sil-9 (check the yellow pages under sand-blasting for a local supplier) which is sold in 40 kg bags for use as playground cover. It is a very inexpensive natural looking gravel with particles of about 3 mm to 6 mm in size. You will need enough gravel to cover the bottom with a layer about 5 cm to 10 cm deep. Gravel is important for more than just holding the plants down. It also allows a slow movement of water around the roots to provide oxygen and trace elements. Potting soil, dirt, and fine sands will pack together too tightly and prevent this essential circulation. The first two will also create an enormous mess in your tank when disturbed.
Water is the other major ingredient. Fortunately, local tap water is fine for almost all plants. Although most books specify water conditions for each type of plant, in practice it’s not very important. This is because most plants are highly adaptable. Unless you live in an extreme part of the country, local pH and hardness are not going to adversely affect most aquarium plants. What is more important is having your tank close to a convenient water source and drain for water changes. Frequent large water changes are the key to success with plants. Tanks which don’t have their water changed regularly suffer from high nutrient levels and may lack certain essential trace elements. Every aquarist should invest in a hose long enough to drain and fill their tanks. Hauling buckets of water is hard on the back and not very conducive to frequent water changes.
Adequate lighting is the most critical piece of equipment to have on hand. Natural sunlight is far too intense and difficult to control to be useful for aquarium plants and so some type of artificial lighting is required. Unfortunately, the hoods commonly sold with most tanks are not intended for plant growth. Instead, most are designed for keeping algae (and plant) growth to a minimum. Good results require the equivalent of one fluorescent tube for each 15 cm of tank width (i.e. a 30 cm wide tank requires two fluorescent tubes). Better results can be obtained with a system which allows variable light intensity, so algae growth can be kept under control. With fluorescent fixtures this means that the height above the tank should be adjustable. Incandescent fixtures can use bulbs of different wattage’s or a dimmer switch. I prefer using a combination of regular 60W bulbs and 75 W indoor floodlights. Halogen bulbs can also be used but these are so bright that care must be taken to prevent excessive algae growth. Dirty lids or glass shields, which block the light, should also be avoided. However, in any system the type of lighting is less important than the ability to control it. Too much light causes algae and not enough causes poor plant growth.
Lighting fixtures suspended from racks or the ceiling are a good solution for fish room tanks since the height above the water can be adjusted to control the light intensity. More attractive, yet simple fluorescent hoods for show tanks, can be made from wood if one has access to the required tools. I’ve used 1 x 8 pine lumber, teak stained, and finished with gloss polyurethane varnish to make a number of hoods for tanks outside my fish room. With these hoods, a fluorescent fixture is mounted only a couple of inches above the water for maximum light and minimum hood profile. The closeness of the bulbs to the water is a potential shock hazard and a ground fault interrupt (GFI) outlet is a must (it’s also a good idea for any aquarium).
Planted tanks generally require less filtration than other aquaria and so the filter choice is not that important. The major role of the filter is just to keep the surface moving. This oxygenates the water and keeps scum from forming. Effective biological filtration takes place on the large surface area of the plants and so an undergravel filter is unnecessary. There is also a lot of controversy about U/G filters suppressing root growth. My advice is to forget about using them because they just aren’t necessary. My favorite filter is a trickle-type filter that uses an overflow to skim the surface. However, small power filters (such as the Whisper power filters from Second Nature) are also quite adequate.
Strict temperature control in planted tanks is not essential. Often enough heat is provided by the lighting to warm the water to 25C to 28C. If your fish don’t mind small daily temperature fluctuations then other heaters aren’t necessary. Advanced hobbyists may be interested in undergravel heating. This type of heating is supposed to slowly circulate water around the roots and provide optimum plant growth. However, it certainly isn’t essential for good results and novices shouldn’t worry about it.
A rough idea of the type of aquascape should also be prepared before planting. Most aquascapes will require some other decorating elements. My favorite one is driftwood, which I obtain locally from nearby streams and lakes. A piece of cleaned, solid (i.e. with all rot and soft spots removed) wood can be mounted onto a flat sheet of plastic using a few screws. When this plastic base is buried, the weight of the gravel will hold the driftwood in place. The natural appearance of driftwood complements live plants well and it also makes an excellent base for attaching plants, such as Java fern.
Finally, when planning a planted aquarium some thought must be given to the type of fish you want to keep. It is important to keep some fish in the tank because they play an important role in fertilizing the plants and certain species can be quite useful in controlling either algae (Farlowella catfish, bristlenose catfish, mollies) or snails (loaches). Obviously a small, planted tank is not a good home for large fish which require open swimming space or ones which like to dig up gravel. Just as obviously, live plants are not compatible with plant eating fish such as silver dollars, tinfoil barbs, or scats. Also, fish which like to jump are not the best bets for planted tanks without lids. Lids or barriers made of plastic eggcrate (from fluorescent light fixtures) is a good material which allows light in while keeping most fish from jumping out.
SELECTING PLANTS
Good results start with the purchase of healthy plants. These are ones that have green leaves and white roots. Some damaged or broken leaves are inevitable and these minor defects should be removed before planting. Plants with excessive damage, sponginess, no roots, smelly black roots, or evidence of snail or algae infestation should be avoided. Removal of damaged parts is required because the leaf damage never repairs itself. Under good conditions, plants can rapidly replace damaged leaves, but there is no point in starting off with poor quality stock. If there is a choice, always try to purchase taller specimens rather than shorter ones. The taller plants have a better chance of doing well because their leaves are closer to the light.
There are a wide variety of plants for sale in aquarium stores and it is important to learn a little bit about the different types available. Occasionally non-aquatic plants are sold for aquarium use and these species should be avoided. Also to be avoided are any red or purple colored plants These species require very bright light and will often die or revert to green coloration inside the average aquarium. It is also important to realize that many aquarium plants (bog plants) only spend part of their life underwater. They will try to grow above the water (emersed growth) and can get quite big outside the tank. Fortunately, many of these plants only require occasional trimming to keep them under water.
THE FIRST PLANTING
A large number of plants are required for an initial set-up. The best place to obtain large quantities of starter plants is at club auctions. The object in an initial planting is to achieve the highest possible plant density in the tank. The plants can then out-compete algae for available nutrients. Tanks with only a few plants seldom do well, because under these conditions there are so many excess nutrients in the water that algae growth completely overwhelms the plant growth.
The plant species chosen for the first planting should be cheap, fast growing plants such as Vallisneria, Hygrophilia, Cabomba, and hornwort. Other stem plants, Java fern, sword plants, and Cryptocoryne affinis (avoid other Cryptocoryne species for the first three months) are also suitable but more expensive. With all of these plants, a close inspection should be made for snails, snail eggs and algae. Emersed cuttings from Nomaphila stricta (temple plant) or Hygrophilia lacustris (willowleaf hygro) make excellent starter plants because the emersed growth is free of any snail or algae contamination. Unlike other emersed cuttings, temple plant and the Hygrophilia species adapt very quickly to submerged conditions.
Pruning should be performed before planting. Remove yellow or damaged leaves, and for stem plants, make a fresh cut in the stem. For rooted plants, remove any soft brown roots and trim the white roots to about 5 cm in length. Longer roots are hard to plant and rolling long roots up into a ball can lead to rotting. The actual planting is most easily performed in a half-filled tank. Excavate a small hole for each plant and don’t try to jam the plant into the gravel. Insert the plant, push some gravel back into the hole, and then gently pull the plant up to stretch out the roots until the crown (where the roots join the stem or leaves) is just above the surface. There shouldn’t be any roots left sticking out above the gravel since these are subject to attack by fur algae. Once plants have been put into place, resist the temptation to move them around a lot. This is especially so with Cryptocoryne species. These plants may take up to a year to recover from a move. An exception which isn’t planted in the ground is Java fern. This plant needs to be attached to rocks or driftwood. The easiest way to mount this plant is to pin it to driftwood using an ordinary pushpin. Java fern grows fast and soon the pins won’t be noticeable.
Floating plants, such as hornwort, Najas, and Java moss can also be used to help a tank get started. However, too many floating plants can block out too much light. The problem is even worse with small floating plants like duckweed. Once you’ve added them, it’s very hard to completely eliminate them. Therefore, I consider duckweed a pest, just like algae and snails, and recommend that all traces of duckweed be carefully washed out of incoming plants before adding them to your tank.
The new plants will require several weeks to re-establish their roots. During this time both light and nutrients need to be carefully controlled to prevent algae from taking over. Lights should be kept on a timer with a daily cycle of 8 to 10 hours. If algae starts to grow, then the lights are too bright and either the wattage should be lowered or the lamps moved further away from the water. Eventually, a lighting cycle of 10 to 12 hours per day should be used. There is no need to provide longer “days” than this. If your plants aren’t growing well then you need to add more bulbs instead of increasing the day length beyond 12 hours.
The best way to start off a new tank is to have a light fish load. Fish which are good algae eaters, such as mollies, flying foxes, and certain catfishes are good starter fish because they can pick at any algae as it appears. These fish should be fed sparingly to encourage them to find algae and keep the nutrients levels low. Eventually, more fish can be added. The total depends upon a number of factors, but keep in mind that the more fish, the more waste, and if your water changes can’t keep up with waste production, then you have a potential algae problem.
MAINTENANCE
Once established, planted tanks require regular maintenance to look their best. The most important thing of all is frequent water changes. These water changes remove excess nutrients, such as nitrates and phosphates, from the water and reintroduce new ones, such as iron, which are required. Your fish will also appreciate the clean water. I perform weekly water changes of between 50% to 75% per week (remember to use a hose and not a bucket) and I’ve never noticed any fish in distress. However, hobbyists with other water supplies may not be as fortunate and will have to test what their fish can tolerate.
Well-established tanks with heavy plant growth may eventually require some trace element additives to replace essential micronutrients such as iron and manganese. Usually these are present in sufficient quantities in our tap water, but heavy plant growth may require extra supplements. The symptoms of a trace element shortage include yellow leaves, weak growth, and holes in the leaves. However, these problems can also be caused by poor lighting, poor water quality, snails, or plant-eating fish. Before resorting to trace element additives, be sure that these other possibilities are considered. Only a trace element additive specifically designed for aquarium use should be used.
There should never be any need to add nitrogen, phosphate, or sulphate additives to a planted aquarium since these nutrients are abundant in fish waste. Garden or hydroponic fertilizers contain huge excesses of nitrogen and phosphate that will lead to algae blooms. Also many fertilizers contain their nitrogen in the form of ammonium salts, which are highly toxic to fish.
Regular pruning will eventually be required as the plants become established. Old, damaged or dying leaves need to be removed and stem or floating plants cut back or thinned out to prevent them from hogging all the light. Certain bog plants, such as the Hygrophilia species also need to be regularly cut back and replanted to keep them from growing above the water. Pruning certain stem plants will also cause a doubling at each node so that thicker, better-looking plants will result. It is important to remember that a good aquascape always requires open space. It may take some willpower to thin out the necessary space, but a more attractive tank will result.
Finally, any exposed gravel should be siphoned clean on a regular basis. Dead leaves and other organic material accumulating along the bottom are a good substrate for fur algae.
PROBLEMS
Maintaining a nice, healthy planted tank would be very easy if it wasn’t for two problem pests, snails and algae. Snails can cause serious damage to plants, especially to young growing leaves. Expensive sword plants and Aponogeton species seem to be among the most susceptible to snail damage. Unfortunately, it is very difficult to detect the presence of snail eggs on incoming plants since they are colorless, jelly-like masses underneath the leaves. Adult snails can easily be picked off or detached from the plants by dipping in alum solution. Alum, however, doesn’t kill the eggs.
Once snails have become established in a tank, complete removal is very difficult. Copper sulfate treatment is frequently recommended because copper is toxic to invertebrates. However, in alkaline water such as Calgary’s (pH 8.3) copper immediately precipitates out and has no effect. Chelated copper additives aren’t much better, because the chelation reduces the toxicity. The only sure way I’ve found to satisfactorily use copper to kill snails is dangerous and not recommended. It involves removing all of the fish, removing all carbonate decorations (such as shells, coral, limestone or marble), reducing the pH to < 7 with acid (this is the dangerous part), and adding copper sulfate. A copper concentration of around 1 PPM will eradicate all snails in about a day. The dead snails rapidly pollute the tank and so the bodies need to be removed as soon as possible.
Fortunately, such drastic treatment isn’t really necessary because snail-eating fish such as Botia loaches can keep snail populations in check. I’ve never been able to totally eliminate all snails this way but my skunk Botia and clown loaches have kept the problem manageable. Other techniques, such as manually picking out the snails at night, or attracting them with zucchini aren’t very effective long-term solutions.
The many different types of algae are the other major headache with planted tanks. All algae problems (except for brown algae, which grows in tanks with not enough light) are caused by two things, too much light and/or too many nutrients in the water. Therefore, the general solution to all of these algae problems is to keep both the lighting and the nutrient levels (using frequent water changes, a high plant density, and a low fish load) under control.
Checking incoming plants for algae contamination is not a bad idea, but in practice there is no effective way of keeping algae from getting into your tank. Some articles have suggested that a brief dip in dilute bleach solution will prevent algae introduction. However, I’ve found that many plants, especially Cryptocoryne, are severely damaged by this treatment. Even when it’s done under carefully controlled conditions. Chemical algaecides are also not recommended for tanks containing aquatic plants.
Aquarium algae can be broadly categorized as brown, green, slime (blue-green), fur, or thread varieties. The brown variety is seldom a problem and its presence is simply an indication to increase the light intensity. The green variety is the most common one and it is seen on both leaves and the aquarium glass. Green algae can be controlled by algae-eating fish, good water quality, and controlled lighting.
The real problem algae species are the slime, fur, and thread varieties, which technically speaking are not true algae. Slime algae forms brightly colored blue-green mats which can quickly overrun a tank and choke off all plants. It is often a symptom of dirty water and too bright lighting. Fortunately, it is the only algae that can be easily eradicated. Treatment with the antibiotic Erythromycin (EM) for a week will kill off this algae. However, the EM treatment will also affect biological filtration in the tank and so aeration should be increased and feeding stopped during the course of treatment.
Red or fur algae has brownish, short-fibers which cling very stubbornly onto the edges of leaves, driftwood, and gravel. It is commonly found in spots in the tank which attract dirt, on roots which are above the gravel, and on the leaves of unhealthy or slow growing plants. This algae is unsightly and very hard to remove. The best defense is careful inspection and removal of infested material as soon as possible. Keeping the gravel clean will also help. Removable decorations can be sterilized with bleach but fur algae on plants can only be killed using a copper treatment like the one described above for snails. However, prolonged treatment for 1 to 3 weeks with a 0.5 PPM to 1 PPM concentration of copper is required. One problem with this method is that it’s very difficult to tell from the appearance of this alga, whether it is dead or alive. Another problem is that some plants, particularly Vallisneria and to a lesser extent Hygrophilia and Amazon swordplants, are sensitive to this treatment and can be damaged or killed.
Thread algae forms green thread-like strands which may be either short and firmly anchored to the edges of leaves, or long and loosely wound around the plant. The loose species can be easily removed by hand from infested plants while the short ones can’t be removed without damaging the plant. Mollies, rosy barbs, flying foxes, and other fish may help by nibbling on these algae, but the only effective long-term solution is controlling the light and nutrient levels in the tank.
OTHER SOURCES OF INFORMATION
This article has just been an introduction to aquatic plant keeping. Hobbyists seriously interested in this aspect of aquarium keeping will want to learn more. Fortunately there are a number of good aquarium books dealing with this subject in both the club’s library and our local stores. There is also a society, The Aquatic Gardeners Association, which specializes in this area. Their bimonthly journal, The Aquatic Gardener, is an excellent source of information. Finally, for those of you with access to the Internet, more information can be found in the aquatic plants mailing list (http://www.actwin.com/fish/aquatic-plants/), the Centre for Aquatic Plants (http://aquat1.ifas.ufl.edu/), the Aquatic Gardeners Association (http://blake.oit.unc.edu/~fish/aga/), the Aqualink home page (http://weber.u.washington.edu/~aqualink/), and the FINS Fish Information Service (http://www.actwin.com/fish/index.html). ?