Do-It-Yourself Guide To
Compact Fluorescent Lighting For Aquariums

Compact fluorescent lamps, also known as power compacts in the aquarium hobby, are basically a “new” type of fluorescent lamp that is gaining in popularity as the line of compact fluorescents available to aquarists is expanding rapidly and more manufacturers are offering products. They are different from regular fluorescent tubes in that they are single ended, as opposed to the typical double ended construction of most other fluorescent lighting.

One of the reasons they are becoming popular in the hobby is their compact size, which allows one to “pack” more lamps into a light hood to achieve the desired light intensity. Previously, to increase the light in the aquarium without switching to metal halide lighting, the choices were limited to high output (HO) or very high output (VHO) fluorescents. Compact fluorescent lamps now provide another option to the aquarist. Over the last few years there has been an increase in the availability of compact fluorescents with the color temperatures suited for reef aquaria, making them an attractive option.

Compact fluorescent lamps come in several different shapes and each of these has its own subset of sizes and wattages in which they are available, requiring different ballasts and lamps sockets. Unraveling the myriad possibilities and getting the right answers is often a frustrating task. To be a successful do-it-yourself aquarist it is important to understand the terminology, which will enable you to track down the components and talk intelligently to the suppliers.

In my experience, I have often found that even the manufacturers' sales reps and the home and electrical supply stores are lacking in knowledge, which makes the do-it-yourself approach frustrating. I always get the look that says “I don’t think you know what you are talking about, because I have never heard of what you want” from sales people. Sometimes you get lucky and find the right person who can help, but that is most often not the case. If you do find one, consider yourself lucky. These days, my strategy is to walk into the local electrical supplier/distributor with a part number and the manufacturer’s name and ask them to order it for me.

The goal of this article is to make it easier for you as a do-it-yourselfer to put together your own compact fluorescent system. It will also provide you with enough knowledge and terminology to enable you to track down and locate the various components.

Components of a Do-It-Yourself Compact Fluorescent Lighting System

This type of lighting system basically requires the following unique components:
  • Compact fluorescent lamp
  • Ballast
  • Lamp holding sockets and brackets.

    Additional items you will need are common to other lighting systems, such as hood/enclosure, reflectors, wires, fans for heat dissipation and so on. Because these items are common to any lighting system, they will not be discussed here and I will focus only on those that are unique to compact fluorescent lighting.

    Compact fluorescent lamps come in different lengths, diameters and wattages.
    Compact fluorescent lamp

    Compact fluorescent lamps are distinguished by several parameters. The most important ones are: 1) lamp wattage, 2) lamp size and diameter, 3) shape, 4) type of base, 5) starting requirements and 6) color temperature.

    1) lamp wattage

    Compact fluorescents are available in various wattages — 5, 7, 9, 11, 13, 18, 26, 27, 28, 36, 39, 40,50, 55 and 96 watts.

    2) lamp size and diameter

    The different wattage lamps often have different lengths, ranging from 6.5 inches for the 9-watt twin tube compact fluorescent lamps, to the 33-27/32 inch for the twin tube 96 watt lamps. The diameter of the lamp is measured in increments of 1/8 inch and is specified using the letter “T”, followed by a number that indicates how many 1/8-inch increments make up the diameter of the lamp. For example, the T5 designation implies that the diameter is 5/8 inch.

    3) Shape

    Compact fluorescents come in different shapes, such as twin tubes, triple, quad and square.

    Here are some examples of the different bases available for compact fluorescent lamps.
    4) Base

    Different compact fluorescents have different bases, a different number of pins and pin placements and locating elements — hence, they require different lamp sockets. This is done to prevent the wrong lamp from being used with a ballast.

    5) Starting requirements

    Compact fluorescent lamps are available in 2-pin and 4-pin configurations. The ones with two pins typically have starters built into the base and these are usually operated with magnetic preheat-type ballasts. The 4-pin lamps can be ballasted by electronic or magnetic preheat or rapid start ballasts, and can also be used with dimming ballasts.

    6) Color temperature

    Just like regular fluorescent tubes, the compact fluorescents are also available in a wide range of color temperatures. For most of the hobby requirements, the lamps of interest have color temperatures of 4300 Kelvin (K), 5000 K, 6500 K, 6700 K and blue lamps (also sold as 7100 K). The 4300 K is not adequate for reef aquaria, but may be suitable for freshwater planted aquariums.

    Lamp designation

    There are two different industry recognized names used for identifying the compact fluorescent lamps — The American National Standards Institute (ANSI) lamp designation and the National Electrical Manufacturers Association (NEMA) lamp designation.

    There are five fields used under the ANSI designation, separated by "/". These are:

    1st field — lamp wattage
    2nd field — lamp length and diameter, measured in increments of 1/8 inch
    3rd field — specifies the shape (i.e., T = twin, Q = quad, M = multi and 2D = square)
    4th field — base
    5th field — starting characteristics (i.e., PH = prehead and RS = rapid start).

    For example, ANSI : 13W/7T4/T/GX23/PH specifies a 13-watt compact fluorescent lamp that is 7 inches in length with a lamp diameter of 1/2 inch (4/8 inch). The shape of the lamp is a twin tube construction and it uses a GX23 type base. The ballast type required is a preheat ballast.

    The NEMA designation is smaller and only includes the following fields: 1st Field — lamp type and shape, and wattage, and 2nd Field — base (e.g., CFT13W/GX23).

    Each of the major lamp manufacturers also have their own trade names, such as Osram’s DULUX, Phillips’ PL, GE’s BIAX and so on. These are also popular ways to refer to the lamps.

    Although, there is a large variety of compact fluorescent lamps, the choice of lamps for aquaria is limited by the color temperature of the lamp. There are very few that have the right color temperature and those lamps labeled as industry specific are often not found in the general consumer lamp catalogs. So, obtaining the right part number is often difficult. Furthermore, some of the lamps are imported from Germany and Japan and not listed in the U.S. catalogs. A good source for aquarium-specific lamps are mail-oder aquarium supply stores (e.g., Champion Lighting). Table I shows a list (not exhaustive) of the various lamps that would be useful in the reef hobby, along with their designations.

    Useful Lamps for the Reef Hobby, along with their designations
    (Information taken from manufacturer catalogs.)
    Lamp type Base Manufacturer Part
    9 watts 5000
    Kelvin (K)
    Twin G23 Sylvania CF9DS/850
    5000 K Twin G23 Phillips PL-S9W/50
    5000 K Twin G23 GE F9BX/SPX50
    Blue Twin G23 Sylvania CF9DS/blue
    5000 K Quad GX10q-1 Panasonic FDL9E50*
    6700 K Quad GX10q-1 Panasonic FDL9E67*
    13 watts 5000 K Twin GX23 Phillips PL-S13W/50
    5000 K Twin GX23 Sylvania CF13DS/850
    5000 K Twin GX23 GE F9BX/SPX50
    Blue Twin GX23 Sylvania CF13DS/blue
    5000 K Quad GX10q-2 Panasonic FDL13E50*
    6700 K Quad GX10q-2 Panasonic FDL13E50*
    27 watts 5000 K Twin GY10q-4 Panasonic FPL27E50*
    6700 K Twin GY10q-4 Panasonic FPL28E67*
    5000 K Quad GY10q-4 Panasonic FDL27E50*
    6700 K Quad GY10q-4 Panasonic FDL27E67*
    Blue Quad GY10q-4 Panasonic FDL27EB*
    5000 K Linear Quad GY10q-4 Panasonic FML27E50*
    6700 K Linear Quad GY10q-4 Panasonic FML27E67*
    Blue Linear Quad GY10q-4 Panasonic FML27EB*
    28 watts 5000 K Quad GX32d-3 Panasonic (U.S.) FDL28EX/D
    5000 K Linear Quad 2G11 Panasonic (U.S.) FQL28EX
    5000 K Twin GY10q-5 Panasonic FDL28E50*
    6700 K Twin GY10q-5 Panasonic FDL28E67*
    Blue Twin GY10q-5 Panasonic FDL28EB*
    39 watts 5000 K Twin 2G11 GE F39/36BX/SPX50/RS
    40 watts 5000 K Twin 2G11 GE F40/30BX/SPX50/RS
    50 to 55 watts 5000 K Twin 2G11 GE F50BX/SPX50/RS
    5000 K Twin GY10q-7 Panasonic FPL55E50*
    6700 K Twin GY10q-7 Panasonic FPL55E67*
    6700 K Twin 2G11 Osram
    Blue Twin GY10q-7 Panasonic FPL55EB*
    Blue Twin 2G11 Osram
    96 watts 5000 K Twin GY10q-8 Panasonic FPR96E50*
    6700 K Twin GY10q-8 Panasonic FPR96E67*
    Blue Twin GY10q-8 Panasonic FPR96EB*
    * Imported lamps not listed in U.S. catalogs

    As you can see, Panasonic and Osram-Sylvania have the most useful lamps based on color temperature. Unfortunately, these higher wattage lamps tend to be imported and are not easy to get through local electrical distributors. The best sources for these lamps are also the mail-order aquarium supply stores (e.g., Reefers).

    The two popular manufacturers of compact fluorescent fixtures in the hobby, Custom Sea Life and Hamilton Technologies (1-800-447-9797) , use the Panasonic and Osram lamps respectively. The lamps are not interchangeable between the fixtures because they use different bases, but can be operated using the same ballasts.

    Here are some examples of the different ballasts, from Advance, Tri-tek and Fulham.


    As with any fluorescent lamp, the compact fluorescents are also operated by ballasts. The ballasts used for these lamps can be electromagnetic or electronic. Some compact fluorescents contain a ballast built into the lamp and are designed to be screwed into a regular incandescent lamp socket. Others have a segregated ballast just like the standard fluorescent lamp system. Most, if not all, compact fluorescents require a special ballast due to their unique size and operating characteristics.

    The simplest way to identify and locate a part number for the ballast is to determine the ANSI, NEMA or manufacturer’s code for the lamp, and look for it in the catalog of the major ballast manufacturers. This will give you a quick way to determine the part number of the ballast needed for your application. You can call the major manufacturers or visit their web sites to get a catalog or view on-line catalogs. Table II provides a listing of the various ballast manufacturers.

    Some Manufacturers of Ballasts
    for Compact Fluorescent Lamps
    Manufacturer Web site Phone number
    Advance Lighting www.advancetransformer.com (800) 322-2086
    Magnetek www.magnetek.com (800) MAGNETEK
    Osram-Sylvania www.sylvania.com (978) 777-1900
    Fulham www.fulham.com (310) 277-9484
    Tri-tek Lighting, Inc. (888) 999-0401
    Hatch www.hatchtrans.com (813) 288-8006

    Ballasts for compact fluorescent lamps are available in one or two lamp configurations. The price difference between them is typically quite small. However, a ballast designed only for two lamp operation will not function with only one lamp.

    In addition to the major manufacturers of ballasts (e.g., Advance, Magnetek and so on) there are several other smaller manufacturers of electronic ballasts for compact fluorescents. With some electronic ballasts (e.g., Tri-tek and Fulham) a single ballast can accommodate a wide range of lamp wattages. Some will also allow either one or two lamps to be used as long as the specified lamp wattage is not exceeded. Hence, these ballasts are a good value.

    Table III provides a list (not exhaustive) of part numbers of various ballasts that can be used with the compact fluorescents commonly used in the hobby. I have identified at least one manufacturer and corresponding part number for the ballast. Armed with this, you can ask your local electrical supplier to cross-reference the part number for a different manufacturer.

    Parts numbers of various ballasts
    that can be used with compact fluorescent lamps
    Watts Manufacturer Ballast
    of lamps
    9 watts Advance EM H-2B9-TP two
    Advance EM H-1B9-TP one
    Fulham EL two
    13 watts Advance EM H-1B13-TP one
    Advance EM H-2B13-TP two
    Fulham EL two
    27 watts Advance EL R-1BP27-TP one
    Advance EL R-2BP27-TP two
    Fulham EL one
    28 watts Hatch EL SWB26-2-120 two
    IceCap EL ICECAP3000 one or two
    39 watts GE EL B140R120HP one
    GE EL B240R120HP two
    GE EL B340R120HP one
    40 watts Osram-Sylvania EL QT1X40DL one
    Osram-Sylvania EL QT2X40DL one or two
    Osram-Sylvania EL QT3X40DL three
    GE EL C240I120RH one
    GE EL C240I120RH two
    GE EL C340I120RH three
    Advance EL REL-1TTS40 one
    Advance EL REL-2TTS40 two
    55 watts Advance EL REL-1TTS50 one
    Advance EL REL-2TTS50 two
    Osram-Sylvania EL QT1X54PHO one
    Osram-Sylvania EL QT2X54PHO one
    IceCap EL ICECAP3000 one or two
    96 watts Advance EL REL-2S-110-RH-TP two
    Osram-Sylvania EL QT2X96/120HO two
    IceCap EL ICECAP 660 four
    IceCap EL ICECAP 660 four

    My personal choice for the low wattage lamps is to go with the Fulham electronic ballast, given its wide range of applicability, from 9 to 28 watts. It will allow two similar lamps to be driven as long as the total wattage is below 35 watts. I have not tried to run two lamps of different wattages with this ballast.

    For the higher wattage lamps, the Advance ballasts are a good choice, given the low price and wide availability. The Fulham 100 ballast is also nice, given its small size and low weight. Unfortunately, so far they only make a ballast that will drive one 55-watt lamp. On a cautionary note, some of these ballasts might light the lamps, but not match the exact specification of the lamp and may, therefore, affect the light output and lamp life.

    Look for the distributors of the major ballast manufacturers in your area. If you can’t locate them call the manufacturer and ask for their distributor or a retail outlet in your area. If you still can’t find a source, try Grainger. For the other ballast manufacturers, such as Tri-Tek, Fulham and Hatch, call the company directly using the information in Table III to get a price quote and dealer information.

    Different lamps require different lamp holders (sockets).

    Lamp Holders (Sockets)

    Compact fluorescents with different wattages, maufactured by different companies, will probably have different bases and thus require different lamp holders (sockets). The manufacturers and part numbers for the bases of the lamps are listed in Table IV.

    To identify sources for these, once again call the manufacturer (Leviton, 1-800-323-8920; Edwin Gaynor Co, 1-800-EGAYNOR) and ask for a distributor/supplier in your area or order directly from them. Grainger does carry some of the sockets. So far I have been able to find the sockets by ordering them through the local electrical suppliers using the part numbers listed in the table. Although part numbers for only Leviton and Edwin Gaynor Co. parts are listed, I am sure there are enough competitors that make similar parts, and your local electrical supplier may be able to obtain them from different manufacturers. The brand name for the sockets is Kulka.

    Parts numbers for various bases
    used with compact fluorescent lamps
    Base Manufacturer Part number
    G23 Leviton 26719
    Edwin Gaynor Co. 1181-9-HOR
    GX23 Leviton 26720
    Edwin Gaynor Co. 1181-13-HOR
    GX32d-3 Edwin Gaynor Co. 187-D3
    Edwin Gaynor Co. 286-SC
    Leviton 13452
    Plastic lamp
    support clip,
    slide on
    Leviton 23452-A
    Plastic lamp
    support clip,
    screw mount
    Leviton 23452-B
    Plastic lamp
    support clip
    Edwin Gaynor Co. 787-2
    Plastic lamp
    support clip
    Edwin Gaynor Co. 787-5

    The sockets for the Panasonic lamps are a little more difficult to find. You may be able to get them directly from Custom Sea Life or try the mail-order places. Custom Sealife makes a nice waterproof socket for their lamps. I recently ordered a pair for the 4-pin square configuration of the Panasonic (Custom Sealife) lamps from Marine Depot. These sockets work for the 96-, 55- and 28-watt lamps. It seems that any generic GY10q socket will work for the Panasonic lamps in these wattages.



    Putting together a do-it-yourself compact fluorescent lighting system is not a formidable task. Using the information provided in this article, I hope you will be able to locate all the various parts you need and enjoy an easily doable do-it-yourself project.

    Acknowledgements — I would like to thank the several aquarists who sent me lamps to test with the various ballasts: Eric Borneman, John Rice, Chris Paris and Doug Kevis.

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