Freshwater

Make sure the lighting system is unplugged when you put it on top of your
tank. Do not plug the unit in until you’re sure it’s stable! You (and your fish)
can be electrocuted if lighting falls into your tank.
Looking at bulb types
You have several bulb options to consider:
Chapter 6: Equipment and Other Technical Stuff
Tungsten (incandescent) lighting is used in household lamps. Tungsten
lighting is not good for aquariums because it is too hot, burns out
quickly, produces excess algae, has a limited spectrum, doesn’t show
your fish’s colors very well, and distributes light unevenly. You may see
colored tungsten lights in your pet store, but avoid them. You will often
find these in all sorts of 1960s disco colors including red, blue, and
green.
Actinic blue bulbs produce long-wave ultraviolet radiation. This type of
lighting is great for plant growth but also produces an abundance of
algae if you have it on a lot. It is used often in marine tanks.
Metal halide lights produce a very pleasing effect in your aquarium
because they have a high red and yellow spectrum and are very bright.
Unfortunately, they are very expensive. These are great for heavily
planted freshwater tanks because they are made to produce properties
similar to natural sunlight.
High-powered mercury vapor lights can hang over aquariums and are
often used to light very deep tanks. Mercury vapor lights are a little
short in the green and blue wavelength department and may need supplemental
lighting to complete a full spectrum. The cool thing about
mercury vapor lights is that they usually retain 90 percent of their original
capacity over a period of several years.
Fluorescent lighting is great for aquariums with live plants. They last a
long time, do not emit excessive heat, and have an even spectrum of
light. There’s a fluorescent light to match almost any system you plan to
set up. Even though they continue to burn, fluorescent lights often begin
to dim and lose a portion of their power after about six or seven months.
This type of bulb brings out the natural colors of your fish and plants.
Whichever lighting you choose, make sure to purchase it from a pet store.
Even though a hardware store can sell you a replacement bulb that fits your
hood, these bulbs were not intended for that purpose and will not provide
good lighting.
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