Published December 18, 2012
Equipping your tank with the right aquarium lighting system will not only impact the aesthetic appeal of your tank, but it could also have an effect on your tank inhabitants. Some species of fish prefer low lighting while others thrive in brightly-lit tanks. If you plan to cultivate a planted tank, you will need to equip your tank with a high-intensity lighting system powerful enough to provide for the needs of many aquarium plants. Choosing an aquarium lighting system is more than just picking the right type, however – it also involves finding a balance in terms of wattage, lumens, intensity and spectrum. Every freshwater aquarium is different so it is up to you to perform some basic research in order to customize your lighting system to suit the needs of your tank inhabitants.
Problems with Intensity
When it comes to the intensity of aquarium lighting
there are two problems you may run into – the light may be too intense or it might be too dim. In cases where the lighting is too intense, you may experience problems with excess algae growth
. Algae are photosynthetic organisms which means that they use light as an energy source to facilitate biological processes – the more light available, the faster they will grow. Fortunately, there are several ways to go about solving this problem. One option is to replace your lighting system, or simply the lamp itself, with one that is less intense. If you have a small or shallow aquarium, there is little need for a high-powered lighting system like VHO or metal halide systems. Another option is to install more live plants in your tank – these plants will benefit from the intense lighting and will also compete with algae for nutrients, thus limiting its growth. If you feel that your lighting system is sufficient for your tank size but you suspect that it might be a little much for your fish, try adding some floating plants to diffuse the light a little bit.
In cases where the lighting in your tank is too dim, there is little you can do aside from replacing the bulb or upgrading your system entirely. Certain lighting systems are recommended for certain types and sizes of tanks so if you do not choose the right system at the beginning, you may end up having to replace it down the line. One possibility is that the lamp you are using is simply not bright enough – try switching to a bulb that offers a greater lumen per watt output or simply install a supplemental light fixture. If the lighting system itself is the issue, you may need to upgrade. Keep in mind that planted tanks
require more lighting than fish-only tanks and the deeper your tank is, the more power you will need in a lighting system. For very large or deep tanks, especially heavily planted tanks, VHO or metal halide systems are recommended – for standard fish-only or lightly planted tanks, standard or compact fluorescent systems are generally sufficient.
Lumens per Watt
In order to achieve the proper balance in your aquarium lighting you need to not only select the right system, but you need to install the proper bulb as well. Aquarium light bulbs come in a variety of different shapes, sizes and intensities so it can be a challenge to find the right one. You may be familiar with the rule stating that fish-only tanks require 1 to 2 watts per gallon and planted tanks 3 to 5 watts per gallon. While this rule is a good starting point, it is definitely not the most important factor to consider – the watt is a unit of power used to measure how much energy any given light bulb uses. Based on this information, you may be able to see how the wattage of any given bulb is not necessarily an accurate measurement of its usefulness in aquarium lighting applications. A more useful measurement is the number of lumens per watt a bulb produces.
Lumens are used to measure the amount of visible light emitted by a light bulb – this information is much more useful in producing the right balance in your freshwater tank. The higher the lumen per watt output of any given bulb, the more intense the lighting is likely to be. This information is particularly important if you plan to cultivate a planted tank because live plants require 10 to 12 hours of intense lighting per day in order to thrive. When shopping for light bulbs, check the lumen rating and divide it by the wattage of the bulb – this simple calculation will provide you with the lumen per watt output of the bulb.
Cultivating a thriving freshwater tank is all about balance – not only do you need to achieve the right balance with your tank inhabitants, but you also need to create a balanced environment in terms of lighting and other tank conditions. Aquarium lighting can be very confusing but if you are equipped with some basic knowledge
about how it works, you should have no trouble achieving a healthy balance in your freshwater tank.