Without appropriate regulation the chemical and physical conditions in it will very quickly go from one extreme to another. Thus fish and plant life in the aquarium is not possible without corresponding control by the aquarium operator. The following factors need to be considered while set up any aquarium.
Tank Selection
Obviously the most essential piece of equipment there is. There are a variety of size shapes and even materials to choose from. Careful thought is needed before choosing any aquaria.
Material
Advantages
Disadvantages
All Glass
This is the material most often used. Sheets of glass bonded together by silicone.
Relatively cheap, Easy to clean, scratch resistant. Easy to repair.
Fragile and brittle, which make it easy to crack. The silicone edge can be peeled away and result in a leak. The tank corners are particularly prone to damage. Scratches that do occur cannot be treated. Curved pieces although available are very expensive.
Plastic
Often used for small cheap tanks.
No joints to fail. Very cheap.
Easily scratched. Easily cracked. Impossible to repair. Usually small in size.
Acrylic
Although technically a plastic I am treating it as a different option. Used for large and expensive aquaria and other quality aquatic equipment.
More clear than glass. Relatively light. Easier to shape. Stronger and more impact resistant than glass. Scratches can be polished out.
Easily scratched. Very expensive. Can't be repaired.
Size of the Tank
Unless the tank has been measured to fit in an alcove I would suggest that you get the biggest size that you are happy with. Most people replace their first tank because it is too small to meet their requirements. Not only that but large tanks offer a more stable environment than do small ones and believe it or not they are easier to retain.
The next deciding aspect is what the tank is for. Discus fish and angelfish require a deep tank of at least 15 inches. Fast swimming open water fish requires an aquarium at least 36 inches in length. African cichlids require a lot of rockwork and unless it is built like a wall at the rear of the aquarium (which looks very unnatural and is no use to the fish) a tank at least 18 inches wide will be required. Obviously it goes without saying that if large fish are to be kept then a large tank around will be required.
Shape of the Tank
There are a lot of odd shaped tanks around now too, and whilst these might look trendy they would be a nightmare to landscape and maintain. I have lately seen:
- A 5ft deep hexagonal column 18 inches wide containing angelfish. The problems of maintaining such a tank would be immense. No standard air pump will work at that depth, a temp. Gradient would form; cleaning the tank would be a real job. Hex tanks are bad enough but this with the extra intensity, don't do it.
- Two tanks connected together by a broad clear pipe. Quite how the connecting pipe would be kept clean and free from unsightly algae and other dirt is anyone's guess. And unless the two halves were absolutely level there is a chance of a very rapid and catastrophic failure.
- Picture frame tanks, which are no more than 3 inches wide and hang on the wall. These tanks are so small that they could house no more than 4 or 5 small tetras and soon look tatty because they are so unrealistic.
It is better to stick to the more common shapes, which are very practical to use and offer great screening. They can easily be made to any size and if in/on a specially built cabinet they can be made to fit into any room.
If something really special is called for there are bow fronted aquaria, but one big drawback is if they break on the front they are uneconomical to repair.
Heating the Substrate
A proper heating system (a low-voltage bed heating system) influences life in the aquarium very decisively: the heating cable (on the bed of the aquarium) integrates the entire bed soil into the chemical and physical cycle of the aquarium by means of the upward current of water caused by it. This ideal aquarium heating system fulfils numerous requirements simultaneously:
Controlling the Temperature
The same temperature in the water and in the bed, just as in natural waters. (If the aquarium water is heated up e.g. by means of heating bars, only the water becomes tropically warm whilst the bed soil remains at room temperature and the plants notoriously suffer from "cold feet").
Continual Supply of Nutrients
Bed water currents which prevail in natural waters are copied; nutrients are fed to the roots, the materials discharged by the roots are carried away. A stable redox potential in the bed. The bed is prevented from turning black and an optimum stock of iron is supplied to the plants, as in tropical waters.
Safety
Absolute safety for man and fish, even if the heating cable is damaged.
Proper Lighting
A good lighting system is needed to reproduce the natural light in fishes and plants natural biotope both in fresh water and in sea water in an tremendous manner. The system should fulfill the two important functions of light:
a) To put the underwater world in the proper light setting
b) To supply the needed energy for plant growth
Criteria for Aquarium Lighting
1. Light's most important function is to provide the aquarium plants with enough energy for optimum metabolism; amongst other things the assimilation of nutrients incl. CO2 and the discharge of oxygen to the water. In the aquarium this is also easy to check by measurement of the oxygen. Towards evening 100 % oxygen saturation should be achieved.
2. The light day under water is shorter in tropical waters than the light day above water. This is a consequence of the angle of refraction in the water. The sunrays do not penetrate the water until they are at a certain height above the horizon. Thus the light day under water amounts to approx. 8 to 10 hours. The consequence for the aquarium: strong light but a shorter period of illumination. Even 14 hours do not bring about 100 % oxygen saturation.
3. Many plants which are used in the aquarium as foreground plants, e.g. echinodorus tenellus, lilaeopsis nova-zelandiae etc., grow on embankments and receive the most light there. If the lighting is weak though, they will obtain too little light in the aquarium, incorporate only inadequately and rot.
Water Stability
Tropical waters, especially flowing waters have a astonishing degree of solidity independent of the season, water level and light conditions. Factors such as the pH-value, the CO2 content, degree of hardness etc. have only a slight fluctuation range. Several functions are also dealt simultaneously by the CO2 system, which assures stability in the aquarium:
Constant pH-value
In the optimum community aquarium in which tropical fish from geographically and chemically different waters can be cared for, a neutral pH-value setting is suggested. Both fish from weakly acidic waters (e.g. neon fish) and also those from slightly alkaline waters (e.g. Lake Malawi or Lake Tanganyika) find an optimum tolerance range here. The CO2 system also offers great return for specialized aquariums in which special fish species, e.g. discus fish, can be cared for or bred. Due to the precisely determined CO2 dosage (pH-Control) both acid and alkaline pH ranges are able to be programmed and set so as to be stable.
Stable Carbonate Hardness
If an aquarium suffers from CO2 deficiency, the following sequence will occur: - Carbon is chemically bound in the carbonates. Now the plants need this carbon, since a different source is not available. In this process, so-called biogenic decalcification, carbonates are destroyed. As a consequence the carbonate hardness drops to dangerously low values and the pH-value becomes extremely unstable, however, with sufficient CO2 supply the plants utilize the carbon contained in the carbon dioxide. Biogenic decalcification no longer occurs and the stability of the water is assured.
Optimum Carbon Supply
Submerged water plants meet their carbon requirements preferably from gaseous, solute carbon dioxide in the water. The supply from carbonates, which is also possible leads as described above, to greater problems. Optimum carbon supply is assured by CO2 fertilization.
The CO2 Table
This table will assist in determining the exact requirements of any given aquarium, particularly in respect of CO2 fertilization. It confirms the rule that optimum pH regulation by means of CO2 diffusion leads to the optimum availability of carbon for the plants. It also highlights the exceptions to this rule, however, in that water containing a carbonate hardness of less than 3 to 4 degrees can suffer a shortage of CO2 very quickly. In fact at neutral pH-levels the CO2 content is already very low! In the case of a carbonate hardness less than 3 to 4 degrees the pH-value should be decreased to 6.4. Under these conditions even the CO2 test can show misleading results if the carbonate hardness is less than 3.5 degrees due to the presence of humic acids, high nitrate values, and other substances that "fool" the test into thinkine that CO2 is present.
Plant Nutrition
Contrary to tropical plant waters, our tap-water has large nutrient deficiencies. Many important plant nutrients and map out elements are missing or extracted from the water during treatment at the waterworks. However, if a nutrient is missing, even if only temporarily, the plants' growth will be stunted or the plants perish. In order to ensure healthy plant growth in the aquarium, the nutrient deficiencies in the tap-water have to be stocked up and supplemented, so that good "aquarium water" is derived from tap-water. For this reason it is critical that the nutrients are in a very certain ratio to one another. Several "critical nutrients", in particular iron and a series of trace elements, present special problems in solving this task; they are required in only minute quantities. In larger doses their effect is poisonous. In aquariums they may not be administered for days and weeks in advance, e.g. if the water is changed. The situation is rendered more serious if various trace elements are not only being consumed by the plants but also being precipitated by chemical reactions. This has always presented plant fertilization in the aquarium with special problems.
Biological Filtration
Aquariums are basically over-populated with fish relative to their water volume. Metabolic products from fish, but also from snails, plants and other sources build up and contaminate the water. The aquarium owner counters this process by changing the water regularly and by means of suitable filtration. Purely mechanical filtration by means of cotton wool, carbon, clay tubes etc. is being replaced more and more by "biological" filtration. "Biological" means: filtration by means of a medium colonized by bacteria which remove all materials contaminating the water and thus assure cleaning of the aquarium water. Specific bacteria are also able to even regulate the remains of chelate compounds and over-fertilized chelated. Industrial discharge water techniques also make extensive use of this filtering technique. Regeneration of the contaminated water is possible up to the point of drinking-water quality.
Strong Water Movements
Good to strong water movements are the following reasons:
I. Water movement having an effect from the surface of the water down to the bed soil will assure even temperatures in all zones of the aquarium.
2. Only a strong movement of water will manage to carry away organic waste materials lying on the surface of large-sized plant leaves. e. g. Echinodorus, Cryptocorynen, Anubias etc. If there is excessively weak water movement, adhesion forces firmly hold a constant film of water on the leaves' surface, thus hindering interchange processes or even eliminating them altogether.
3. Water zones with fresh nutrients reach the leaves surfaces by means of water movement.
4. Provide a strong current for the fish. Many fish need this, especially those coming from speedy flowing streams.
Dense Planting
The optimum aquarium is dependent on dense and well growing plants. The advantages of a well planted aquarium are:
- Well growing plants provide optimum oxygenation.
- Well growing plants are an excellent protection against algae of all kinds.
- Well growing plants inhibit disease causing organisms.
- Decorative overall impression.
- The substrate is kept in shape by the roots.
- Oxygen is released by the roots to all areas of the substrate.
- This prevents the substrate from turning black.
- Well growing plants remove toxic elements from the water.
- Several aquarium plants release antibiotic-like substances in the water.
- Dense planting provides good hiding and spawning places.
The solution for an optimum aquarium:
I. Use pre-cultivated plants adjusted to aquarium conditions.
2. The aquarium must be densely planted from the very beginning. Use many different types of plants that crow slowly, stay small and crow offshoots. Tall growing plants that float on the surface must be regularly trimmed back to prevent them from cutting out the light to the plants underneath. Plants should not really get taller than the aquarium.
3. All growth factors have to be met.
Balanced Fish Population
A balanced fish population goes hand in hand with the idea of providing both fish and plants with an environment that is optimally designed. In the optimum aquarium fish and plants should be a pleasant combination.
Here are some basic rules:
- Do not mix fish that are mismatched.
- Do not add fish that eat plants.
- Make sure you introduce algae eating fish right from the start, see also "Algae prophylaxis".
- Make sure the fish you put in all have the same temperature requirements, usually 25 to 26oC (76-78oF).
- To prevent an excessive snail population, a snail eater may be added.
- Choose fish that occupy all levels of the aquarium: Bottom, top and mid level.
- Do not add picky eaters if you are not sure that you will be able to provide them with the food they need.
