| "In this installment, filtration, fertilization and fish are some of the topics examined"
As noted in the first half of this article, live plants have proven more than a little difficult for the majority of hobbyists. Although the problem can be as simple as insufficient lighting, there are usually several factors working in combination that finally convince the aquarist to give up and use plastic plants instead. Once the correct relationships among these factors are understood, however, growing live plants successfully becomes much easier.
FILTRATION
In a densely planted aquarium with a very low fish load,there is no need for filtration - the plants consume all the waste produced by the fish. During the day, the fish utilize the dissolved oxygen produced by the plants as photosynthesis takes place. However, plants do not produce oxygen at night. Instead, they consume dissolved oxygen in direct competition with the fish in the tank. To ensure sufficient levels of dissolved oxygen at night for both plants and fish, it is best to add a few airstones to create agitation at the surface,where the exchange of oxygen and carbon dioxide takes place.
There are, however, good reasons to use a filter. Plant leaves must come in contact with a constant supply of fresh water in order to extract nutrients and minerals from it. The circulation provided by filters is one way to achieve this. Also, even though a densely planted tank with a low fish load does not require filtration, many hobbyists are prone to overstocking their aquariums and filtration will eventually become necessary.
Although you may use an undergravel filter in an aquarium without live plants and never give it a second thought, be aware that there is some controversy about using undergravel filters in planted tanks. Many aquarists claim that undergravel filters do not harm their plants at all. In such situations,the tanks probably do not have any additives in the gravel and do have ha heavy fish load that compensates for the loss of carbon dioxide in the water (utilized by plants during the day) that occurs with these filters.
I do not use undergravel filters in my setups for the following reasons. 1) Undergravel filters will disturb the gravel-additive layer and cause a large, brown mess! 2) With undergravel filters that are powered by airstones, the vigorous flow of water to the surface removes vital carbon dioxide that is crucial for the survival of plants. 3) Undergravel filters create an unnatural water flow through the substrate around the roots of the plants.
My personal preference for filtration in a planted aquarium is a canister filter. These filters can be used to promote gentle water circulation by placing their intake and output tubes at opposite ends of the tank.
In planted tanks without undergravel filters, the gravel may turn black in some locations, indicating anaerobic (lack of oxygen) conditions. The gases in these areas are very toxic to the tanks's inhabitants. This situation can be prevented by cleaning the gravel more frequently with a gravel hydro-vacuum or by planting live plants throughout the bottom of the tank. The plant roots will keep the bottom of the tank free of dangerous anaerobic pockets. An undergravel filter will also eliminate the problem.
Although the exchange of gases at the surface is generally encouraged, there should not be too much surface turbulence or water flow through the tank during the day, because this removes carbon dioxide that is needed by the plants for photosynthesis. In tanks with very little surface agitation, some of the proteins in the water accumulate on the surface, forming a thin coating or foam. This reduces light penetration into the deeper parts of the tank. The use of activated carbon in the filter or attaching a surface skimmer to the intake tube of the canister filter will correct the problem.
TEMPERATURE
Plants do best at temperatures of approximately 73 to 77 degrees Fahrenheit (23 to 25 degrees Celsius). Although some fish may seem comfortable at 80 degrees Fahrenheit (27 degrees Celsius), plants should not be kept at such high temperatures because carbon dioxide and oxygen do not dissolve as easily. Most plants, however, will tolerate temperatures in the mid-80s for extended periods of time if necessary.
It is important to keep the roots of the plants warm. Both root and leaf growth are promoted by warmth in the substrate. A cold substrate can injure or, in some cases, even kill plants. Such situations arise only when the aquarium is kept in rooms that are significantly cooler than the aquarium water. Therefore, it is a good idea to attach a stick-on thermometer on the outside of the aquarium at gravel level.
In an aquarium with sufficient water circulation and equipped with a high-quality heater, the water and the substrate should be approximately the same temperature and there should be no need to heat the substrate. Circulation of the tank water will also prevent stratification of the water into layers. Without adequate mixing of the water, the coldest water settles to the bottom.
If the substrate temperature varies significantly from that of the rest of the aquarium, you may want to install an additional heating device. An undergravel cable heating system controlled by a thermostat is one method. This will heat the gravel and the tank bottom while discouraging anaerobic areas in the gravel. Unfortunately, these systems are very expensive and not widely available in North America. A heating pad that sits under the tank will also work and is less expensive. Loss of heat through the bottom of the aquarium can be prevented by placing a styrofoam sheet under the glass for insulation.
WATER CHEMISTRY
When it comes to live plants, water quality is very important. A basic understanding of water chemistry parameters, such as pH and hardness, goes a long way toward solving some of the problems you may encounter in growing aquatic plants.
In most parts of the country, tap water is hard and alkaline. If you use tap water in your aquarium, plants such as Elodea and Vallisneria, which are adapted to growing in hard, alkaline water, will prosper. Plants that prefer softer, more acidic water will gradually become less healthy. Most plants grown in aquariums originate from natural areas with soft water and therefore will rarely do well in water of significantly different composition. There are only a few plants that will thrive in just about any kind of water.
Softer water can be achieved by diluting tap water with collected rain water or distilled water, or by using a reverse osmosis unit. Rain water should be collected in a clean bucket in an open area and must be filtered through activated carbon before use.
You can also create softer water by filtering it through peat moss or by using commercial water-softening resins. However,both of these methods have their disadvantages. Peat will soften and acidify the water in the best way possible for aquatic organisms, but it will tint the water brown and reduce light penetration. Commercial resins will not color the water, but they remove some essential minerals that must be compensated for by adding tap water. All of these softening methods must be performed before the water is added to the tank.
In a densely planted, well-lit aquarium, minerals from the water are exhausted very quickly during photosynthesis. These minerals will have to be replaced on a weekly or bi-weekly basis in the form of partial water changes. Tap water usually contains most of the minerals needed by plants. Infrequent or irregular water changes soon take their toll on plants - leaf size and growth rate will remain very low. Some species of fish may tolerate infrequent water changes, but plants won't.
FERTILIZING
Plants require essential nutrients and minerals just as humans do. The four essential nutrients needed for plant growth are carbon, nitrogen, potassium and phosphorous. Plants get their carbon from carbon dioxide, which dissolves in aquarium water. In hard, alkaline water, the dissolved carbon dioxide is present in the form of bicarbonates. Hard-water plants are adapted to utilizing bicarbonates, but soft-water plants perish in hard, alkaline water. It is therefore essential to be aware of the origins of your plants and try to provide them with the type of water best suited to their needs.
The recent introduction of the carbon dioxide diffuser offers one way of supplying sufficient levels of carbon to your planted aquarium. This device diffuses controlled amounts of carbon dioxide into the water, providing carbon for the plants and maintaining a constant pH (by the formation of carbonic acid). Cost may be a prohibitive factor here - this equipment is not inexpensive. The good news is that reasonable success can be achieved without it.
The situations with the three other essential nutrients required by plants (nitrogen, phosphorous and potassium) vary. There is often an excess of the first two in aquariums due to the presence of fish wastes, which contain nitrogen and phosphorus compounds. Plants can easily absorb these from the gravel and water. If you look at the contents of the fertilizers many aquarists pour into their tanks, you will notice that they contain large quantities of nitrogen and phosphorous compounds! Therefore, you do not need to add excess amounts of these nutrients if your tank already carries a high fish load.
Potassium, on the other hand, is found in lesser quantities in aquariums (it is present in tap water). This being the case, coupled with the fact that your plants may not need extra nitrogen and phosphorus, I recommend that you buy trace elements (sometimes sold as micro-nutrients) for your plants instead of fertilizers.
The most important trace element required by plants is iron. Small amounts of iron can be found in water, but it is chemically unstable and consequently not available to plants for very long. To compensate, you may purchase mineral supplements, such as Ferroplant(TM), which contain stable (chelated) iron. Instead of administering a large dose on a weekly basis, these supplements should be used at one-third dosages three times each week. Large doses can be toxic!
Laterite is another means of providing iron to plants. Laterite is a type of tropical clay that is high in iron. It is usually available in the form of small balls or cubes that may be purchased through your dealer or by mail. Laterite can be inserted directly into the gravel near a plant or mixed generously into the lower half of the gravel while preparing the substrate.
The decomposition of fish waste in the filter also releases some of th minerals utilized by plants. As noted above, aquatic plants receive other trace elements through weekly partial water changes. Regular water changes are therefore very important for plant growth.
FISHES
I recommend small schooling fish for the planted aquarium. The list of suitable species is nearly endless, but you should stay away from herbivorous fish. Silver dollars, severum and leporinus, to name a few, are capable of denuding your planted tank in just a few days. Many large cichlids will uproot plants near their territory or spawning sites, but there are also many cichlids that will not bother the plants at all. Research the habits of any species you wish to add to the tank before you buy them.
Once you have released a fish into a densely planted tank, it is extremely difficult to capture it again using a net. You can save yourself a lot of trouble if you make certain that a new specimen is free of disease (this means quarantining for at least two weeks!) and compatible with the other residents before introducing it into a planted aquarium. This reduces the possibility that you may have to remove it.
When it comes to feeding the fish, the same rules apply for fish in a tank with live plants as for one without live plants. Feed your fish sparingly and remove excess food soon after. Many years in the hobby have shown me that fish do not die of starvation! Healthy fish can go without food for up to 10 days, sometimes even longer. Overfeeding will cause your fish to produce more waste. An accumulation of waste will create problems with algae and disease and will greatly compromise the water quality in your tank.
ALGAE
Algae is considered a pest by most aquarists. It is present in small amounts in every tank, and it gets there by way of water, plants and even air. It is important to remember that although algae is a simple form of plant life, it has similar requirements to those of higher plants. Algae is relatively easy to control if a few simple rules are followed. Notice I said control, not eliminate. The goal is to minimize the obvious presence of the algae, which is always in the tank.
Algae thrives in conditions where higher plants cannot. Plants may not grow in a dimly lit aquarium with large amounts of dissolved fish wastes, but algae will flourish. However, in a well-lit, densely planted aquarium, the plants will compete with the algae for the excess nutrients in the water and reduce the possibility of an algae takeover.
When you first set up your tank,it takes about a week or two before the plants establish themselves and begin to grow. Algae can establish itself much faster and can proliferate in your tank within just a few days. To avoid this problem, I advise you to plant the tank densely with fast-growing plants as soon as you set it up. One Amazon sword is not enough to keep algae under control. Fast-growing plants include Anacharis, Vallisneria, Hygrophila, water sprite, hornwort and duckweed.
If, despite all your best efforts, algae does show up in your tank, there are several ways to control it. Some methods used by hobbyists require a little effort, whereas others are rather destructive. One simple approach is to reduce the number of fish in the tank. A high fish load generates greater amounts of fish waste, a favorite food source for algae.
You may want to add algae-eating fish to your planted aquarium. Algae constitutes a large portion of the diet of many species of fish. These fish can be used in aquariums to effectively control algae growth. Some suitable species include Hypostomus spp., flying foxes (Epalzoerhynchus siamensis), Otocinclus spp. and mollies.
Thoroughly inspect all rockwork, plants snails, wood and so on for algal filaments before introducing them into the tank. Remove any algae you see. After the tank is running, check these items periodically for algae growth.
Frequent partial water changes are essential for controlling algae. Wastes accumulated through fish metabolism and uneaten foods will elevate the levels of nitrates and phosphates in the tank, which must be removed on a weekly basis through partial water changes. Failure to carry out partial water changes will adversely affect plant growth and the well-being of your fish.
By the way, when rinsing reusable media from a filter, do so with tank water, not tap water. Rinsing in fresh tap water, which may contain chlorine or chloramine, can destroy many beneficial bacteria living on the media.
Providing your planted aquarium with the proper amount of light will go a long way in controlling algae. Exposure to direct sunlight will promote significant algal growth. As mentioned in the first half of this series, installing the correct type of lighting and illuminating your tank for no more than 10 hours per day will also keep algae in check.
There are numerous factors at work here. For example, a sudden change in or removal from the aquarium of a vital requirement, such as light intensity, carbon dioxide or a certain nutrient, can trigger an algal bloom.
To reiterate a point, avoid excessive fertilization of your plants. There are many fertilizers that supply nutrients already existing in your tank, while omitting many essential trace elements. Adding this type of fertilizer to your tank will cause an algal bloom. If an essential trace element is absent, the plants will stop growing and the added fertilizers will remain unused, providing food for the unwanted algae. This is especially true if the tank is poorly lit. In brightly illuminated tanks, plants assimilate fertilizers more quickly, thereby using up any nutrients that might otherwise be utilized by algae.
Use a balanced fertilizer that contains trace elements. Better yet, as noted earlier, use trace element supplements that do not contain nitrogen, phosphorous or potassium.
Your tap water itself may contain too many nutrients, especially if you live near a farm and use well water. Farm fertilizers can seep into your water source, resulting in excessive algae growth. To prevent this, use one of the water softening methods mentioned above. It may be worth the cost to have your water analyzed by a professional lab.
I advise against the use of algicides because they not only kill algae but your plants as well. Although manufacturers may claim that algicides will not harm higher plants, I believe that they do. These chemicals should be used only as an absolute last resort.
PLANTS
Unfortunately, it is impossible to cover all plant species or even a single genus in the space allotted. There are many books that can help you choose the kind of plants your tank will best accommodate. It is wise to read as many of these books as possible, because each provides slightly different information. Reading these books can prevent you from making mistakes, such as purchasing an Echinodorous cordifolius for a 10-gallon (38-liter) tank - this Amazon sword will grow more than twice as big as the tank! Almost all aquarium societies have at least one member who is an expert on plants and will be of tremendous help. A reliable dealer may also be a good source of information.
As noted earlier, you will need hardy, fast-growing plants as soon as you set up your tank. After they have become established (in about a month or two), you may either keep these specimens or replace them with more delicate, slow-growing plants.
PURCHASING PLANTS
You can purchase plants either from your local dealer or through the mail. Even in large urban areas, there are generally only a few pet stores that assign a significant amount of tank space to aquarium plants.
It is critical to be able to tell a healthy plant form one that is not. Make sure the leaves look crisp and healthy. The roots should appear pale and firm - dead roots are brown and limp. Very often, plants are kept in dark, crowded tanks. Avoid these plants, because they usually shed all their leaves and die soon after you bring them home. Plants are prone to stress, just as fish are. It is also very important to buy enough plants at the same time to combat the initial nutrient instability of the aquarium.
Plants from reputable growers often come in small plastic pots that protect the roots from damage. These may be planted as they are - the pots permit the roots to grow out and some of the cotton or sponge padding contains plant fertilizers. It is also acceptable to remove the plants from the pots.
Before purchasing any plant, it is a good idea to identify and read about it. You may find that some books do not contain any information on certain plant species. This could be because the plant is not an aquatic species at all but rather a marsh plant that normally has its roots in moist soil or in water and its leaves above the water. These plants vary in their tolerance of submersion. Many species available to the hobby are marsh plants that can adapt to permanent submerged living. However, there are also numerous species that will die if completely submerged. This can sometimes explain why certain plants never do well in your tank.
Once you get your plants home, clean them thoroughly. This removes parasites as well as snails and their eggs. Some aquarists disinfect their plants by soaking them in a solution of alum or potassium permanganate, but if you purchase plants from a reputable dealer and inspect them carefully, you can usually avoid doing this.
MAINTAINING A PLANTED AQUARIUM
If you have succeeded in getting your aquarium to look the way you want it to, don't ignore it and expect it to take care of itself. If you do, the tank will not remain beautiful for long. Planted aquariums do not need much more care than any other type of tank, but the care you provide must be on a regular basis. The most important task is the partial water changes I have emphasized several times already.
Gardening is another regular maintenance task you need to perform. Otherwise, one or two fast-growing species will dominate the tank, stealing the light from the shorter plants growing below. Remove any dead leaves you may find. This will do more than simply make the tank look better - decomposing dead leaves consume a lot of oxygen and leach out nutrients that may encourage algal growth. Don't forget to add iron and minerals to your tank at least once a week, although, as noted earlier, smaller doses used more frequently are more beneficial than large single doses.
Planted aquariums require the same basic tank maintenance as unplanted aquariums. For maximum efficiency, keep your filter clean and free of debris, such as dead leaves. Vacuum the surface of the gravel carefully so that the roots of the plants are not disturbed. In a lightly stocked tank in which the fish are not overfed, this need by done only occasionally. Replace fluorescent tubes every six months to maintain their intensity.
A well-maintained planted aquarium provides your fish with a healthy, natural-looking environment. Aquatic plants contribute to better water quality in the aquarium and make fish feel much more secure.
Besides, a beautifully planted tank really attracts attention. Don't be surprised if visitors to your home walk straight past you to your planted tank before they even greet you. You can live with such annoyances, can't you?
PLANTING
There are a number of important things to remember when planting your aquarium.
It may be necessary to trim the ends of the roots if they are too long. This will not harm the plant.
Never cover the crown of a rosette plant with gravel. The crown is where the roots begin. A rosette plant has no stem but grows straight from roots to leaves with a small stubby crown in the middle.
Be careful not to stir up the gravel-clay mixture on the bottom of the tank.
Large or tall specimens should be planted in the rear and small plants should go in the front.
Plants need room to grow. If large plants are kept too close to each other, they will look unattractive and encroach on each other's growing space.
Always plant stemmed plants, such as Ludwigia and Ambulia, in groups of six to 15. Stemmed plants look much better if they are in groups - they lose their visual effect if planted singly. For the same reason, avoid planting large decorative plants, such as some of the Echinodorous and Aponogeton, in groups. check your reference books to see how large your plants will grow.
Place plants with similar leaves apart from each other. Plants such as Cabomba, Ambulia and water milfoil; Ludwigia, Bacopa and Hygrophila polysperma; or Aponogetons, Amazon swords and large Anubias will not look very appealing if planted together due to lack of contrast. If plants with similar appearances must be kept next to each other, at least place an interesting piece of driftwood or rock in between them. The idea is to maximize contrast, not only in the shape of the leaves but also in the color and size of the plant. A good example of contrast is red tiger lily and vallisneria.
In order to achieve a more natural appearance, avoid any symmetry in your planted aquarium. The left half should not resemble the right in any way. Don't plant a large plant in the middle of the tank. This divides the tank in half and force the viewer's attention to one side or the other. Always plant your impressive centerpiece slightly away from the center of the tank.
Leave open spaces away from the center to give the appearance of depth. These open spaces give fish swimming room. For these spaces you may have a mat of Java moss growing on the bottom or perhaps just an attractive selection of rocks. A tank that is densely planted from one end to the other without any open space will look like a jungle no matter how beautiful the growth is.
If you use rocks, use the same kind throughout the tank. It's best to use more than two rocks of varying sizes.
Choose fish that will occupy different levels of the tank. This, along with the placement of the plants, will give the aquarium a natural, balanced appearance. |
