Proper Care Of Aquarium Plants
The addition of water plants to your aquarium increases the beauty of the tank and often the health of the fish. Choosing the right plants is only half the battle, taking care of the plants is equally as important. Aquarium plants have four basic needs: proper lighting, a balance of CO2, the right mixture of nutrients and the correct trace elements. While providing the right things at the right times may be tricky, it is essential in the proper care of your aquarium plants.
Plants use light to photosynthesis, the reaction that produces food for the aquarium plants and creates energy for the tank. Although aquarium plants usually only require light from the blue of red spectrum to make energy, it is more aesthetically pleasing to the eyes of you and your viewers if you use light from all spectrum ranges. Although more expensive doesn't always mean better, this is one case where money matters. Cheaper light bulbs tend to be dimmer and not provide the light intensity that water plants need to effectively photosynthesize. Also important to note that light bulbs should be changed frequently, at least every 6 months and preferably on a rotating schedule instead of all aquarium bulbs at once. Aim for a wattage between 1.5 and 3.0 for every gallon of water the tank holds. Aquarium plants in deeper tanks will require more intense lighting.
CO2, more specifically dissolved CO2, is usually necessary for the plants in the tank to effectively photosynthesize light and nutrients. A small amount of CO2 is released from the fish in the tank but it will likely not be enough to enable the aquarium plants to grow and produce energy. Carefully read the CO2 requirements of the water plants you choose since different plants have different needs and higher levels of CO2 can negatively influence some plants. Tanks with no added CO2 range about 1-3 ppm while most plants need about 10-20 ppm to most efficiently grow. This means that most tanks with aquarium plants will require some sort of CO2 injection.
Plants get a good deal of their needed nutrients from water and CO2, including hydrogen, oxygen and carbon but aquarium plants also need two other nutrients in order to flourish. These two nutrients are potassium and nitrogen. With enough fish in the tank, the plants will simply absorb nitrogen from the ammonium found in fish waste. Some plants transfer ammonium into nitrate before utilizing it but most plants will simply use the ammonium directly since it requires less energy to convert. Potassium proves more of a challenge to owners of aquarium plants since it is difficult to test for proper levels. Most fish food contains potassium and it is general practice that if there are enough nitrates in the tank than there is also an acceptable amount of potassium in the water.
Trace elements are any material that the aquarium plants only need in a very small amount but are still essential to the growth of the plants. Common trace elements include sulfur, calcium, magnesium, iron, and phosphorus. The first three trace elements on this list are usually found in tap water although water that is considered especially soft may be lacking calcium or magnesium. The level of nitrates in the water will also let you know if there is enough phosphorus. Special chemicals need to be added to prevent the iron in tap water from oxidizing into a form that aquarium plants cannot use.