That is a good question and the answer may be due to the fact that the Odyssea “T6†marketed by AquaTraders has the same G13 connector found on many T6, T8, T10 and T12 bulbs.
The AquaTraders “T6†has the same diameter as a T5 and a length similar to that of a T5. AquaTraders lists its “T6†length as 45.75-inches (
http://www.aquatraders.com/index.asp?PageAction=VIEWPROD&ProdID=340). This is closer to a T5 length than a T6 which is normally 2 inches longer. The endcap appears to have a G13 connector instead of a G5 miniature bi-pin. G13 medium bi-pin connectors are normally seen on T8, T10 and T12 bulbs. G5 miniature bi-pin connectors are normally seen on T5 bulbs.
I purchased my “T6†bulbs from Natural Lighting and here is what Natural Lighting claims:
“T6 The Next Generation of T5 Lamps, Universal wattage. T5.5 lamps are direct replacements for standard T8 or T12 fixtures. No need to buy expensive T5 fixtures, or retrofit existing fixtures to use shorter T5 lamps. T6 have stand bipin (G13 base) connection, and are standard lengths (24â€Â, 36â€Â, and 48â€Â). These lamps have thicker glass, which are more durable, and operate at slightly lower temperatures than standard T5 lamps. The T6 lamps will operate with T8 electronic ballast, and T5, 54 watt ballasts. The T6 provide 10% to 40% more light output than standard T8 lamps.†(
http://www.naturallighting.com/pdf_files/aquarium_lighting_t5bulbs.pdf).
The “T6†bulbs that I ordered replaced the T12 bulbs in my combination metal halide & fluorescent fixture. Although they were 55-watt T6HO bulbs, they produced normal output with the 40-watt electronic ballasts of the T12 fixture. They actually appeared brighter because their smaller diameter blocked less light from the T12 reflectors.
As for lighting standards, a local lighting salesman told me that any shop can order fluorescent bulbs with any connector, length, and diameter regardless of “standards.â€Â
