01-06-2010, 08:16 PM
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#1 | | | A Basic Approach to the Natural Planted Aquarium--Part Four A Basic Approach to the Natural Planted Aquarium—Part Four Having discussed nutrients, substrate and water parameters in Parts One and Two, and filtration in Part Three, we come now to the light and on-going maintenance. Light is the single most important aspect of a planted tank. In large (3 feet in length and larger) tanks, fluorescent lighting is the most efficient for the type of planted aquarium under discussion; it is low in heat production, relatively inexpensive to operate, and there are a number of different types. For smaller tanks, incandescent fixtures work fine with the compact fluorescent bulbs now available; here again, the light is good (depending upon the bulb type), heat production is very minimal, and the bulbs have more intensity for less watts so they are energy efficient. The colour temperature of light (which has nothing to do with intensity) is expressed in Kelvin. The sun at mid-day has a rating of approximately 5778K. Full spectrum around 6500K closely replicates the mid-day sun in colour. The lower the kelvin number, the warmer (appears more reddish) the light, and the higher the kelvin number, the cooler (appears more bluish) the light. Kelvin is not always an accurate guide, as different spectrum tubes can produce different light colour. Plants grow by photosynthesizing, and to do this they require light in the blue and red colours of the spectrum; not surprisingly, blue light also penetrates water better than other colours, but red light is also necessary. Many of the so-called “plant” tubes provide light mainly in the blue and red range, but these create a purplish hue to the aquarium, and plant and fish colours will not be natural; they are also usually far less intense so there is actually less light getting to the plants. Full spectrum light, around 6500K, includes peaks in the blue, red and green colours; the green balances, allowing the colours of the plants and fish to appear natural. Studies have demonstrated that aquarium plants grew strongest under a combination of full spectrum and cool blue.[1] With two tubes in the fixture over the tank, it is possible to use one full spectrum and one cool blue. Tubes and bulbs with a rating between 6000K and 7000K usually work the best. However, different manufacturers can alter the colour of the light through the phosphors coating the inside of the tube, so the light may be slightly more "cool" or blue even though the kelvin rating has not changed. In some cases, the "daylight" tubes and compact fluorescent bulbs are closest to this ideal light. Light has to be adequate in terms of its intensity and duration. Submerged plants in nature are basically shade plants, frequently growing not in direct sunlight but in diffused light caused by overhanging vegetation. Most of the fish kept in planted aquaria are forest fish that come from dimly-lit waters and appreciate less intense light. The intensity of light should thus be minimal, just enough to provide adequate light for the plants. Another advantage is that less light means less CO2 and nutrients are required by the plants to balance. The vast majority of aquarium plants will grow very well under less light, around one watt per gallon. This formula works with regular fluorescent lighting, the T8 and T12 tubes. T5 HO tubes produce considerably more intense light, about one and a half times more light than the same length and colour type T8 tube regardless of wattage, so this must be recognized when choosing T5 HO fixtures. Over a 4-foot 55 gallon aquarium as an example, one could choose a regular fixture with two T8 tubes, or a T5 fixture with one T5 HO tube. The advantage with two T8 tubes is being able to mix full spectrum and cool white. In their natural habitats aquatic plants receive 10 hours of daylight and 10 hours of total darkness, with dusk and dawn being the remaining 4 hours. Using a timer is the best way to provide consistent light each day; the duration depends upon factors such as the type of plants and the nutrient availability; with insufficient nutrients, plants cannot photosynthesize and the light will promote algae [remember that law of minimum mentioned in Part 1?] Depending upon the plants and nutrients, light duration can be anything from a minimum of 6 hours daily up to 12 hours and even more. Referring back to the issue of balance: the light duration must balance the nutrients available, including CO2. During the first few weeks after setting up a new planted aquarium, monitor plant growth carefully, and be prepared to increase or reduce the duration of light accordingly. Ensure that the room allows for a minimum of 10 hours of complete darkness each day. Putting It Together—the Balanced Planted Aquarium As Karen Randall has noted,[2] there are two overlapping balancing acts that must go on at the same time in order to achieve a healthy aquarium. The first consists of light, CO2 and other nutrients. The second, which is closely related to the first, is the stocking level and tank maintenance. Maintenance in the form of a partial water change depends upon the fish load in the aquarium in relation to the water volume and plants. In a truly balanced system, the fish stocking would be in balance with the volume of water and number of plants with little need for intervention by the aquarist aside from feeding the fish and the occasional partial water change. But most of us have more fish than can possibly balance the plants and water volume, so the weekly partial water change is an essential part of regular maintenance. The reason is simple: pollution from fish waste. The solid will be broken down by bacteria into liquid, but this "crud" remains in the tank until you remove it. You can rinse the filter often to remove the solid trapped there before it breaks down, and likewise vacuum the open substrate minimally for the same reason. But the "crud" still remains. Unless you have a filter hooked up to fresh water and a drain, all filters simply circulate the water over and over, and this pollution remains. Plants can remove it, but slowly and not enough to sustain the average aquarium. The only way to remove it is the regular partial water change. Fish produce not only waste, but pheremones into the water; these latter cannot be handled except by removal. All of this builds up, day by day. Scientific studies have concluded that performing larger water changes weekly significantly improves water quality.[3] Water stability is usually cited as the reason for regular but smaller water changes. This may be true for water parameters like pH and nitrates in non-planted aquaria, but there is no logic in maintaining more stable pollution in a tank. No one can logically dispute that reducing pollution is a benefit and the more the better; in nature our fish live in water that is constantly changing, and only through partial water changes can we begin to approach that preferred--but in the aquarium unattainable--state. At the same time, a significant weekly water change will actually work to maintain more stability long term in the water parameters. [1] K. Richards, “The Effects of Different Spectrum Fluorescent Bulbs on the Photosynthesis of Aquatic Plants,” Freshwater and Marine Aquarium, July 1987, pp. 16-20. Also Diana Walstad, Ecology of the Planted Aquarium, second edition 2003, pp. 180-181. [2] Karen Randall, “Equilibrium in Planted Aquaria,” Aquarium USA 1998, p. 28. [3] David E. Boruchowitz, “Time for a Change: A Mathematical Investigation of Water Changes,” Tropical Fish Hobbyist, November and December, 2009.
Last edited by Byron; 03-23-2011 at 05:51 PM..
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01-07-2010, 10:37 AM
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#3 | | | Quote:
Originally Posted by issa2010 please u cant support us of pictures ?! | Yes, if you look under the "Aquariums" tab on the left under my name you will find photos of my present and former tanks.
Byron.
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04-16-2010, 05:25 PM
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#6 | | |
Lots of info in these 4 posts. Alleviated some of my concerns about starting up my first planted tank. Thanks!
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