Cheap Lighting for Plants: CF Sprial Bulbs

Cheap, high-output lighting options for smaller aquariums are hard to find. Most are at least $80+ and if you've got a smaller aquarium, it's usually because you don't have the money (or the money for more space) for a larger tank. So, here's a cheaper alternative: Compact Fluorescent Bulbs in an Incandescent Hood. Using CF bulbs, you can put together a lighting unit that can give you up to 50 watts in the space of a 12 inch strip light. The benefits of such a unit are a low cost and comparatively high output and you don't have to buy the bulbs from an overpriced aquarium supplier. For this unit, you need:

• An incandescent strip light - You can use either a full hood like the All Glass Economy Glass Hood (these usually only come in a 10 gallon size) or just the strip light, like this Perfecto Incandescent Strip Light. The benefits of the strip light are that it can be moved and used on any size tank, but it is harder to find in local pet stores and you need to either suspend it (not recommended) or put it on a glass top. It usually costs about $20.

• 2 Full Spectrum Compact Fluorescent Bulbs - You want the screw in variety, not the ones with pins at the base. They also must not be larger in diameter than the light strip they will be used in. Usually, a 25W bulb is about the largest that will fit, unless you can find the non-spiral U-tube variety: then length and the maximum wattage of the strip is the limiting factor (most are 2 x 25W max). These bulbs are quite hard to find in a full spectrum color temperature. Wal-Mart stores often carry a "Lights of America" brand that offers them in Daylight 5500K. Alternatively, many online light bulb sellers, such as 1000bulbs.com or SpecialtyLights.com offer them in spectrums that will work.

There's no altering or assembly required, just screw in the CF bulbs, put it on your tank and off you go! There are a few important things to remember though. Do not expose the bulbs directly to the water. There should be glass or something in between protecting them from water splashes and condensation. Also, the higher wattage bulb you use, the more heat will be generated (more on this below). In a warm climate with no way of cooling the tank, this may cause temperatures to rise to unhealthy levels. This approach certainly offers the most "bang for the buck," but it is not the most efficient means of lighting your tank. Spiral bulbs are less efficient than linear tubes because light exiting the tube has the possibility of reflecting back into another part of the tube, or may just enter another part of the tube directly. This causes light loss and heat buildup and is known as "restrike." So all 50 watts are not entering the tank, but instead some light is being lost in the bulb itself. I haven't been able to figure out or find a figure on just how much light is lost, but it's not so significant that the light output is seriously diminished. The incandescent hoods often don't have any sort of reflector in them (some have a small metal reflector, but it doesn't do much) so some of the light is lost when it is absorbed by the light housing. Regular tin foil can be used to line the housing behind the bulbs which will slightly increase the light getting into the aquarium, but it will block ventilation, causing the bulbs to run much hotter and reducing their life.

If you are looking for the cheapest lighting option with the highest light output, you should consider a CF Spiral bulb unit. Be aware that it is not the most efficent option, many systems are available that offer highly polished and engineered reflectors that give you the same results with a lower wattage because more light is actually getting into the tank. However, these will definitely cost you more up-front.

Pros: Best "bang for your buck" for smaller aquariums, easy to replace bulbs

Cons: Uses more power, creates more heat, less light actually gets into the tank

Total cost: $48: $20 for Incandescent Stip Light, $8 per bulb, $20 for glass hood/canopy