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Practical Fluorescent Info

by "Harold G. Walters" <hgwalters/>
Date: Thu, 4 Dec 1997
To: Aquatic Plants Digest

With the recent questions about low cost lighting, I though this would be helpful. Since I have recently completed building a DIY hood and used T8's with an electronic ballast, I have aquired some understanding of lighting terminology.

First some general resources:

  1. FAQ: Aquatic Plant Q&A
  2. The Lighting section of KRIB
  3. Grainger Catalog under Lighting

All major lighting manufacturers have web pages of some sort, although you may have to dig to find the right information. The Philips pages have the most detailed information.

Philips -

GE -

Sylvania -

General Info

Since the Plant FAQ covers things in general, I am going to talk primarily about standard output four bulb electronic ballasts and energy efficient T8 four foot 5000K bulbs, since that is what I used. The only economic bulb length is really 4 ft, most of the others are more expensive. Of course if your tank is not >= 4 ft long, then you will need other solutions. There are also other considerations such as color temperature and CRI for your situation. There are any number of reasons to go with a common type of bulb, but the biggest ones are cost and availability. Since the goverment passed the Energy Policy Act which mandated that starting in April 1994 many common bulb types could not be manufactured or imported into the US, the major manufacturers have all been pushing energy efficient T8 bulbs.


The bulbs themselves are often called "lamps" and the end caps are often called "lampholders" or "sockets". Every bulb has generic type code and one specific to a manufacturer. If a length is not specified, most often it means 4' lamps. The code F32T8 means

F - fluorescent
32 - watts
T8 - number of eights of an inch in diameter, T8 is 8/8 or 1"

I don't know much about the pin configuration code other than the standard medium two pin T12 and T8 bulb is called G13. Every manufacturer has their own way of describing bulbs but it generally includes F32T8 and a model and color number. I priced most of the following bulbs at about $3.50 each. Most of these are rated at about 20,000 hrs and I feel confident that I can get at least 1 year (3650 hrs) of good light output from them.

Philips - F32T8/TL850
GE - F32T8/SPX50
Sylvania - FO32T8 OCTRON 5000K


I priced the four bulb, 120 volt, 32 watt, instant start, electronic ballasts at about $25 to $30. It was interesting to note that the 2, 3, and 4 bulb ballasts were approximately the same price.

Sylvania QUICKTRONIC QT-4X32/120IS

Lampholders/End Caps

You could get by with standard lampholders if you are willing to replace them when they corrode. I priced them at $2/pair. Or you can spend some money and get water resistant end caps mail order at about $10/pair.

Coralife T8 Endcaps w Clips AF936

Material Costs

Homemade hood $50
Electronic Ballast $30
4 Bulbs $14
4 Pr End Caps w 8 clips $40
Aluminum Foil Reflector
Total $134


I fit four bulbs with endcaps into a 8 inch wide by 48 3/8 inch long space in my hood (inner dimensions).


I put this over a 55 gal tank, which is about 2.3 watts/gal 10 hrs/day and plant growth has been tremendous. I have a vericulite/gravel substrate, DIY CO2 injection, and fertilize with PMDD. Many of the plants have gotten a red pigmentation to protect themselves from light. I think I could have gotten by with less light.

Where to buy

Look in the yellow pages for a metropolitan area under Lighting. Pick out 2 or 3 vendors that look like they offer a wide selection of bulbs and ballasts. Call and ask about fluorescent bulbs and electronic ballasts. Tell them what you want. I bought mine from the store that had everything I wanted in stock.

Harold G. Walters
Up to Lighting <- The Krib This page was last updated 30 July 2000