After buying an aquarium, you have to choose type you would like to create (freshwater – tropical or mild-zone, saltwater – tropical or mild-zone).
The most important thing you have to do is to form a good environment for plants, fish and other animals. Do you ask how? The best way is to put only sandy substrate in the aquarium, granularity 3 – 4 mm, the depth of substrate about 10 cm at the back and 5 cm in front. Use biological and mechanic filters which do not oxygenate water too much (their capacity per hour is lower or the same as capacity of our aquarium), because superfluous oxygen blocks nutriments. Biological filters catch particles dispersed in water at first. After a few weeks, there appear bacteria (they reproduce very fast) which transform particles into nutriments that are consumed by plants. This is called biological balance. However, there are some elements which can be missing (Mg, K, Fe, Mn, Zn, Cu, B, Mo). Therefore we should use some fertilizer for aquatic plants that contains them and which is not synthetic, because these fertilizers contain matters that can accumulate in plants and cause foul leaves and stems. If we have got a good fertilizer, it is necessary to control acidity of water in our aquarium – pH should be between 6.2 and 6.7 and water should not be hard (2 – 5 dKH). Only in these conditions can be elements in the fertilizer effective. Now another important thing: carbon. It is necessary for plants. They need it for being strong and beautiful. The easiest way for them how to get it is to receive CO2. This process is well-known at land plants – in contrast to them, water plants rarely have got enough CO2 in water they grow in. Some species are able to get carbon from carbonates, but they spend much energy and the aquarium must be well illuminated (that is the reason why aquariums with hard water should have very much light). If there are hard spots on leaves of your plants and a hard stripe of sediments a few mm above the surface, it is because plants
Do we have CO2 in our aquarium? To find it out, have a look at the table below:
| carbonate hardness | 60 mg CO2/liter (very much) | 35 mg CO2/liter (optimum) | 10 mg CO2/liter (very little) |
| 2odKH | pH 6.0 | pH 6.3 | pH 6.8 |
| 4odKH | pH 6.3 | pH 6.6 | pH 7.1 |
| 6odKH | pH 6.5 | pH 6.7 | pH 7.3 |
| 8odKH | pH 6.6 | pH 6.9 | pH 7.4 |
| 10odKH | pH 6.7 | pH 7.0 | pH 7.5 |
| 15odKH | pH 6.9 | pH 7.1 | pH 7.7 |
| 20odKH | pH 7.0 | pH 7.3 | pH 7.8 |
