For aquarium lighting, the term is used for twin tube (sometimes called folded tube) fluorescent bulbs. They are more or less equivalent to T5 straight tube fluoresecents with multiple fluorescents so that they have a broad sprecturm output. T5 fluorescents are 5/12 of an inche in diameter. Somewhat similarly folded fluorescentlamps, generally of much smaller size, are twin tube "Compact Fluorescents" or "CFs" that can range in watts up to abut 15 watts, after which the design moves to 4 or 6 tubes or a single tube twisted in a spiral. CFs will fit (sort of) into conventional table lamps and often have the ballast built right into the bulb but not always. CFs are intended to be used in place of incandescent bulbs in household applications to save energy. Fluorescents are about 30-35% effeicient at converting electrical energy to visible light -- the rest of the energy is converted to heat. Incandescents are about 5%-7% efficient -- an absolutely extraordinary waste of energy. CFs, because they are folded into a smaller package --basically folded over on themselves several times or in a sprial -- lose as much as 40% of their light output by shining it on themselves, so to speak, instead of out into the room. They are poor choices for aquarium lighting, in most circumstances since PCs are so much more effective, being folded only once and losing about 10% of their light to shining on themselves. PCs, are possibly the best choice for aquaria. If you want the ripply sparkly effect, then add an MH along with the PCs. One of the best places to get them as kits is from AHSupply.com . Finished PC lamps can be found at most hipper aquarium equipment supply stores. amazingly, many lfss (Local Fish StoreS) don't carry them or the bulbs. I believe I have given a politically correct answer. Scott H. --- Aaron Glass <aglass@wi.rr.com> wrote: > Power Compact Flourescent Lighting. > > Aaron > > www.jeezman.com > ----- Original Message ----- > From: "Mike Roberts" <mike@datawest.net> > To: <aga-member@thekrib.com> > Sent: Saturday, May 03, 2003 6:06 PM > Subject: RE: [AGA Member] I guess im knew to > > > > Hi, > > > > What is a PC? > > __________________________________ Do you Yahoo!? The New Yahoo! Search - Faster. Easier. Bingo. http://search.yahoo.com ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe aga-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/aga-member/