T5 Lighting and the 4-6 Watt/Gal rule.

F

F.N.G.

That New Guy.
Sep 13, 2005
4
0
0
56
Edgewater FL.
I have become very interested in working with T5 lighting. I have a hood that is limited to distance away from the water, and the T5 produces less heat. I have been looking for inforamtion on ballasts and T5 80watt bulbs. They work better to penatrate to the bottom of the tank.

I have gone all over the net and have contacted many Engineers on designs. Programable Dimmable Ballast (NICE) , Thin Outdoor Electronic Ballasts are only a few of the options that are out there.

HTML: 
http://www.osram.dk/B2B/brochurer/HF-forkoblinger_og_transformere/Osram_T5-Fibel_final.pdf

HTML: 
http://www.universalballast.com/

The one problem I'm having is the wattage rule (4-6 watts/ gallon). If the T5 produces more lummens, then therefore I would need less wattage to get the same Lumen output as it would be for a comparable MH...Right?

A 400 watt metal halide system can be replaced with a 6 lamp F54T5HO (Florescent54wattT5typeHOHigh Output, (of course in the right spectrum.) The 400MH system produces 24,000 Lumens and uses 485 Watts to do this. (They are using a Core and Coil Ballast) That comes out to 52.4 LPW (Lumens per Watt). Now understandable that is based on a Non-electronic MH ballast, but if I base the Wattage useage on the bulb alone I still only get 60LPW.

The Universal Accustart F54T5HO 6 lamp system produces 351 watts and 28,440 lumens. That makes 81 LPW at a savings of 107 watts.

I just recieved a F54T5HO Ballast from Universal Lighting to check-out. It's a 54 watt system. The wife wants that ballast for her 55 gal freshwater tank. I'm thinking of ordering the F80T5HO ballasts.

The T5 system is an old technolgy with a new lease on life. The dimable ballasts can be faded over a 2 hour period. Making for a very realistic sunrise and sunset. The only reason that I find that of interest is because I'm using a 125 gal tank as a my headboard. Quiet and smoothness are a must.

I look forward to hear from anyone that has input on this old rule, or to the origin of it.

Thank-you to all of you in advance.

Jamie Beckett
 
A lot of people will tell you the watts/gallon rule has limited usefulness. Lumens are also problematic, because that's a measure of the spectrum our eyes are sensitive to, which does not correlate well with the light corals need.

Ultimately, the measure of interest is photosynthetically available radiation, or PAR. Unfortunately, PAR is difficult to measure reproducibly, and most of us don't have PAR meters at home. You can make a rough approximation using watts/gallon, assuming that PC puts out about 20% more PAR than NO lamps, and halides put out about 40% more. This gets increasingly muddled when one starts to deal with lamps with different color temperatures and reflector designs. For those of us using metal halide lamps, people like Joe Burger and Sanjay Joshi have done an excellent job of measuring spectral output and PAR for most lamps, and many ballasts, that are available.

One of the things that I have found most frustrating is the lack of good PAR comparions between PCs, halides and T5s, but that is starting to be remedied. It would appear that T5s put out more PAR than a lot of halide lamps, but the measurements are still not as systematic as I would like.

The Grim Reefer at Reef Central seems to be the current expert on T5 lighting. You might have a look at this thread: http://www.reefcentral.com/forums/showthread.php?s=&threadid=724967
 
Sheding Some Light On The Subject.

Mr. Mogurnda,

I would first, like to thank your for time to answer me on this subject matter. I now have a wealth of inforamtion to work with on this. I had talk to Osram and universal ballast. I had asked about the PAR values, but didn't understand it enough to know which information to gather. I now have some more homework, and , so far, I'm looking forward to going on my addictive search.

Thank-you again.
Jamie
 
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