If most aquariums are like an aquatic zoo, than a Dutch aquarium is definitely an aquatic garden. These breathtaking aquariums are focused on plants, and usually do not even contain fish at all. If fish are included, then they are usually only present to consume algae, or to accent the plants. Dutch aquariums, although not as a rule, tend to be high-tech units, with expensive CO2 metering equipment and expensive lighting systems. Much energy is spent on mixing the right blend of nutrients into the substrate, and also on regular additions of liquid plant supplements. Having healthy plants needs not be so expensive, however. There are many ways to get the same results using less expensive means.
Plants need certain things to live and grow. They need water, heat, carbon dioxide, light, oxygen, basic nutrients, and trace minerals. Aquariums provide many of these naturally, although not necessarily in the correct proportions. The water must meet the chemical requirements of the plants to be kept. This means that the physical parameters of the water are important to plants as well as fish. The pH, hardness, alkylinity, and salinity affect plants as well as fish. Also, different plants prefer different temperatures. You will not succeed with aquatic plants if you do not attempt to meet the proper temperature requirements of the plants you wish to keep.
Carbon dioxide, or CO2, is necessary for plants to grow. Plants use it in photosynthesis to build sugars to grow. They also use light in this process. This is why it is important to balance these two factors. If there is plenty of CO2 but not enough light, then the excess CO2 does not help the plants. The same is true in reverse; more light will not help the plants if there is not more CO2 as well.
Many people do not realize that plants require oxygen to live. Plants consume oxygen just like animals do. However, during photosynthesis, they produce more than they use and respire the excess. At night, however, they can not photosynthesize and therefor do not produce oxygen at this time but use it just like animals do.
Most of the basic nutrients needed by plants are readily available in the aquarium. These are nitrogen based compounds such as ammonia, and phosphorous based compounds like phosphate. These compounds are used by the plants to build plant tissue, and are also used by algae. In an aquarium, the plants and algae are in direct competition for these nutrients. By planting the tank heavily, there will not be enough left over for the algae to get a good foothold. There will always be algae in a planted aquarium, but by catering to the plants, it is possible to keep the growth of algae limited.
Trace minerals are elements that are used by plants along with the basic nutrients. The most important of these is iron, although there are others such as magnesium that also are required. Most of the trace elements are present to some degree in fish food and waste; however, the plants will begin to show mineral deficiencies if there is an inadequate source of minerals. Yellow, pale leaves that form holes is a symptom of this deficiency. Adding an iron-rich supplement periodically will usually be all that is needed to combat this deficiency. Some plants require a substantial amount more of some minerals than others do, and may suffer while others thrive.
To meet the needs of the plants, one can spend a small fortune on lighting, chemical filters, substrate additives, liquid supplements, CO2 reactors, and other equipment. In my experience, however, it is cheaper and more satisfying to use a do-it-yourself approach. I will soon be adding to this page a section of the easy-to-use methods that have helped me find great success with planted aquariums, including home-made plant supplements, CO2 reactors, and more.