The Peaceful Amazonian Cichlid Community Tank

by Grant Gussie, CAS

originally published in The Calquarium Volume 42, Number 7, March 2000

The South American cichlids are among the most intelligent, personable, beautiful, and interesting fish in the aquarium world. It is not surprising that they are also among the most popular. But cichlid aficionados are a strange lot, and many take great pride in the fact that a lot of South American cichlids are big, nasty, and devoted demolishers of aquarium décor.

Turned off either by the wastelands of gravel piles and uprooted plants left in the wake of an oscar, or by the eye-less, fin-less, and scale-less results of an encounter between two green terrors, many aquarists either avoid South American cichlids entirely, or relegate them to an unadorned tank in the corner of the fish room. Here they are given "cull eating" duties, ridding the fish room of stunted, malformed, or otherwise undesirable fry, but they are often otherwise ignored

It is however entirely possible to have a South American cichlid tank as a showpiece aquarium. Complete with plants, schooling fish and tranquil settings. Such a tank requires planning and careful execution, but it can be done. And you can do it without resorting strictly to dwarf cichlids, or the two famous wimps of the cichlid world, the discus and the angelfish. We can include these if we like of course, but we can also have a lot more variety than that as well.

The secret to the planted cichlid aquarium is to protect the plant’s roots. The easiest way to protect the plant roots is to plant the roots though an "egg crate" type light diffuser of the type sold to cover fluorescent light fixtures. Place the roots of the plants through the holes in the plastic and lay the plastic (plants and all) over a level bed of gravel. Add enough additional sand to bury the egg crate and thus the plant roots. With this method it is impossible for cichlids to uproot the plants, but also, unfortunately, this method makes it very difficult to replant the aquarium once the egg crate is buried…the whole egg crate must be pulled out of the gravel in order to replant. Therefore, I would recommend using small squares of egg crate material, each holding one or two plants, rather than having a single sheet of egg crate covering the entire tank bottom.

A piece of egg crate can also be used to secure to the bottom a "not-quite" sinking piece of driftwood. Not suprisingly, dead wood litters the bottom of most Amazonian biotopes, and so submerged driftwood is a very common and desirable addition to the South American aquarium décor. But keeping the driftwood securely on the tank bottom may be a problem. Try strapping a piece of egg crate to the bottom of the driftwood with a couple plastic wire ties threaded through holes drilled through the bottom of the wood. Slide a piece of flat shale between the driftwood and the egg crate and then bury the egg crate just as you would one holding down a plant. This works much better than methods that glue or screw the driftwood to the shale, as screws and glue do not hold on to water-logged driftwood with any certainty.

With driftwood in place, it is time to choose plants. Amazon sword plants of various types are often the plant of choice for Amazonian tanks, as they are native to the area. However, Amazon sword plants, despite their robust root systems, are not really a good plant to have around cichlids or the plecos that are common tank mates for South American cichlids. Plecos and many cichlids are at least partially vegetarian, and sword plants seem to be their favorite vegetables. For this reason, the tougher sword plants such as Echinodorus osiris are to be preferred to the soft-leafed Echinodorus bleheri. But better still are thoroughly unpalatable plants like Java fern, despite the geographical inconsistency of putting an Asian plant in with South American fish. As a general rule, ferns are less palatable to fish than are flowering plants. Of the flowering plants, tough-leafed "bog" plants like Anubias are less palatable than fully aquatic plants. Of the fully aquatic plants, the thicker-leafed ones like Valisneria are less palatable than ones with thin, translucent leaves. For example Valisneria and Ludwigia make an interesting combination of fast-growing inedible plants that do well in a cichlid tank. The bushy red Ludwigia leaves make a nice contrast to the light-green strap-like leaves of the Valisneria. Both plants, once established, will grow extremely quickly, and thus do much to out-compete algae. Some of the smaller Cryptocoryne would make nice foreground plants. Some Java fern tied to the driftwood also creates a nice affect. And a large sword plant as a centerpiece is very nice, but again, I would recommend Echinodorus osiris over more delicate-looking species.

The cichlids (except for dwarf species) are fairly large for aquarium fish, and need elbow room. I would not recommend anything less than 200 liters for this aquarium, and 400 liters (and up) is very much better. Most cichlids are also "full-bodied", with a lot of body mass for their length. And all cichlids are extremely gluttonous. Therefore be very careful with "inches of fish per gallon rule". A 50 gallon tank most certainly can not support 50 inches of oscars, regardless of the "one inch of fish per gallon" rule. Stock you cichlid aquarium very lightly…no more than half what you think it can hold in terms of fish, and preferably much less than that. I would not recommend anything less than 30 liters of water per medium-sized cichlid, and 50 liters is much better. This will be the best thing you can do to keep in-tank aggression (as well as algae growth) under control.

This tank must have efficient biological filtration. Cichlids are big eaters and efficient ammonia producers, but they are also quite sensitive to ammonia, especially in neutral or alkaline waters. I would highly recommend a plant filter for their algae-fighting and oxygenating abilities. A trickle filter is a strong second choice, as it also an efficient oxygenator, but it does not help to reduce algae growth. Undergravel filters are a poor third choice, as they are detrimental to plant growth and contribute greatly to the tank’s algal growth and required maintenance.

The waters of Amazonia range from pH neutral in larger mainstreams down to an acidic pH of 4.5 in small, clear, "blackwater" tributaries. All Amazonian water is extremely soft. Reverse osmosis or another source of soft water may therefore be worth while, but it really is unnecessary. You can get by without it. If you do use RO water however, make sure you don’t lower the alkalinity below 30 mg/L CaCO3, or a dangerously unstable pH may result. Mixing 1 part Calgary tap water with 3 or 4 parts pure water is a good idea.

You may also want to use CO2 injection to lower the tank pH to near neutral, as this will assist your plants.

Several of the plants recommended above (especially Ludwigia and Valisneria) are "bright light" plants. So every effort should be made to supply at least 1 watt of high quality fluorescent lighting for every 2 liters of tank capacity. This can only be economically done if you build your own hood.

So we have set up a large tank with a running bio-filter, adequate illumination, a large piece of driftwood, and lots of plants of the recommended species. What fish do we get?

First of all, let’s only discuss fish that are (at least occasionally) available in the better local aquarium stores. To go through all of the acceptable South American species would be impossible, but if you have an opportunity to get a more unusual species described as "peaceful", feel free to use it to substitute any of the suggestions below.

A beautiful group of cichlids are the earth eaters. They make up the genera Geophagus, Gymnogeophagus, and Satanoperca. These fish get their name from their habit of chewing and spitting out sand in order to find invertebrates. All this sand sifting means they have special requirements. A plant-free area of coarse sand or very fine gravel is recommended. Of these fish, the beautiful and commonly seen commercial "jurupari" (Satanoperca leucosticta) is quite peaceful and highly recommended. I’ve never seen the true jurupari (Satanoperca jurupari) but expect its temperament would be similar to leucosticta. The Brazilian earth eater (Geophagus braziliensis) and the red-hump earth eater (Geophagus steindachneri) are commonly available earth eaters, but they are somewhat bossier than the juruparoids. But they can certainly be considered for this tank as well. All of these fish are very difficult to sex until they are fully adult, so buy at least six youngsters to be sure to get a pair.

The "smiling acaras" of the genus Laetacara are highly recommended fish. They are available intermittently in the better aquarium stores. They are smallish cichlids, to about 8cm length. Some consider them dwarf cichlids, even though they are considerably heavier than the Apistogramma species. The most commonly seen species is Laetacara dorsigerus but it is usually misidentified as Laetacara curviceps in dealers’ tanks. They are usually sold under the common name curviceps. These fish are very attractive, with the males having very a nice wine-red throat and sides. A pair or two would make a very nice addition to this tank. Give them their own little cave or piece of driftwood to hide under.

The true dwarf cichlids of the genera Apistogramma and Mikrogeophagus can also be considered. These fish must be given small caves to reside in, either coconut shells or hollow driftwood. You are however unlikely to see much of them as they would tend to stay close to home and may not be noticed in such a large tank. They are better displayed in smaller quarters.

In a very large tank one could include the chocolate cichlid (Hypselecara temporalis), but not without some careful consideration first. Although they are peaceful toward other species, these are huge brutes that can cause a great deal of destruction without any particular effort. They can also be very aggressive toward their conspecifics at breeding time, so only a mated pair should be considered. These fish are also large and predatory enough to pop Apistogramma down like peanuts. Large males do however develop a lovely wine-red head and they are most impressive animals.

Another cichlid that is recommended is the rainbow cichlid, Herotilapia multispinossa. I have never understood either this fish’s common name or its scientific name, as it is neither a tilapine nor is it even remotely "rainbow" colored. Instead, this fish has a pleasant, but not gaudy, coloration of olive-green, yellowish, and black. Rainbow cichlids are smallish cichlids, to about 10cm in length, and quite peaceful. They are also ridiculously easy to breed and almost impossible to kill. I once had a female disappear from a tank…only to finally be found three months later inside a filter pipe (having snuck inside it when I temporarily removed the strainer and turned my back). After three months of continuously swimming against the current without any food, she finally lost the battle and ended up in the filter, where she was discovered; weak, thin, but very much alive. She recovered fully in less than two weeks of normal feeding.

Pretty much all of the "flattened" cichlids would go well in our peaceful tank, but the discus (Symphysodon species) might be a bit too shy for this community. More suitable would be the severum (Heros species), the angelfish (Pterophyllum species), and the festivum (Mesonauta species). Each of these get along very well as either mated pairs or in groups of at least six. All are docile, elegant, and beautiful. None will uproot plants, although the severum will take the odd bite out of one. The uaru (Uaru amphiacanthoides) would be a very nice fish to include as well, but these fish get extremely large, so need at least an 800-liter tank.

Cichlids, despite their ruffian reputations, are actually quite skittish animals, and if they are the only fish in the tank you might not see them very often. An active school of smaller fishes does wonders in keeping the cichlids feeling secure enough to stay out in the open. These "dither fish" as they are called, can be any schooling fish that will not harass or be eaten by the cichlids. Any of the larger round-bodied tetras are very good, while small tetras like neons are likely to be considered food. Any of the hatchet fishes make very good dither fish for cichlids smaller than the chocolate cichlid, as the hatchet fish cruise around at the surface, out of the cichlids’ way. It is important to keep the hatchet fishes’ tank carefully covered, however.

Additional tank mates that are also recommended are the Corydoras catfish and any of the medium-sized sucker-mouthed catfishes, like Ancistrus or Sturisoma. Very small suckermouths like Otocinclus are likely to be eaten, and very large suckermouths like Panaque will almost certainly chew your plants down to the gravel line. The same holds true for silver dollars (Metynnis species) and head standers (Anostomus species), which would otherwise make excellent choices as tank mates.

Below are a few suggested communities for relatively peaceful cichlid aquaria. All tanks are assumed to be set up as per instructions given above. Try to give at 20 to 30 liters of water per small cichlid (curviceps or rainbow cichlid), 30 to 50 liters of water per medium-sized cichlid (severum, festivum, jurupari, or angelfish), and at least 80 liters of water for each chocolate cichlid or uaru.

  1. Smallish Tank (200 to 400 liters). Six severums or angelfish or festivums, one pair curviceps, one Sturisoma, six Corydoras, six medium-sized tetras.
  2. Medium-sized Tank (400 to 800 liters). Six severums or angelfish or festivums, two pair curviceps, one pair rainbow cichlids, six Corydoras, four Sturisoma, ten medium-sized tetras, ten hatchet fish.
  3. Medium-sized Tank (400 to 800 liters). Six jurupari, one pair rainbow cichlids, six Corydoras, four Sturisoma, ten medium-sized tetras.
  4. Large-sized Tank (800 to 1200 liters). Eight jurupari, eight severums, six Corydoras, six rainbow cichlids, four Sturiosoma, twenty medium-sized tetras, ten hatchet fish.
  5. Very Large Tank (> 1200 liters). Mated pair chocolate cichlids, eight uaru, eight jurupari, eight Sturisoma, ten Prochilodus.
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