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View Full Version : Changing make-up of light fixture?


thbrewst
01/31/2012, 08:50 AM
I have a 72" Hamilton fixture with 3 175w MH (mogul) and 4 96w PCs over a 175 gal tank. I am generally OK with this fixture but have debated switching over to LED. As with most the cost plus infancy of the technology is scarring me off a bit. So I was also wondering what it would take to simply change out the inards of the fixture that I have now. There are 2 fundamental things I would want to tweak if it were somewhat cost effective.

MH, I do not think that the 175w is giving me as much light as I would like to have. I would prefer to bump this up to 250w. So first question; can you switch this up by simply replacing the ballasts and the bulbs or is there more to it than that? Is the wiring different? The socket different?

PCs, given that PCs are slowly going out of the market I would prefer to switch these out for T5s. I am not sure what the difficulty would be to wire and install something like this into the fixture or how many it would take to at least equal the 4 PCs I have now. Also would I need to add ballasts or could I reuse what I have. I think there is a Fulham Workhorse 5 driving each PC today (so I have 4 ballasts).

Thoughts? Does any of this make sense versus just saving the money and replacing the fixture?

sirreal63
01/31/2012, 09:53 AM
You can do the switch you are looking at, but first what is the ballast and the bulbs you are using for the MH? Changing the PC's to T5 would be a little harder but would be much better. You could use the LET Retro from ReefGeek and rip out the PC's and the crappy workhorse ballasts and switch to a higher PAR 175 watt bulb and not worry. The wiring and socket will not have to be changed inside the fixture if you go with 250 watt ballasts but I would do the T5 first as it would make the most difference. You should be able to fit 4-60" bulbs in the fixture, but measure it first to make sure you have room.

thbrewst
01/31/2012, 11:26 AM
You can do the switch you are looking at, but first what is the ballast and the bulbs you are using for the MH? Changing the PC's to T5 would be a little harder but would be much better. You could use the LET Retro from ReefGeek and rip out the PC's and the crappy workhorse ballasts and switch to a higher PAR 175 watt bulb and not worry. The wiring and socket will not have to be changed inside the fixture if you go with 250 watt ballasts but I would do the T5 first as it would make the most difference. You should be able to fit 4-60" bulbs in the fixture, but measure it first to make sure you have room.

I am using an older PFO Ballast (all 3 MH powered from 3 ballasts in a single housing with separate switches) and I think CoralVue 14k bulbs.

I wasn't aware that my florescent ballasts were not good ones.

I'll take a look at the replacements you are talking about on ReefGeek.

Thanks.

sirreal63
01/31/2012, 11:45 AM
Workhorse ballasts will light the bulbs, but are not correct for T5. The LET Retro has the correct ballast and unless something has changed, is about as good of a high PAR retro as you can find. The bulbs you have aren't really great for PAR but switching to the Iwasaki 15K will double the PAR of your existing fixture, in fact it produces more PAR than many 250 watt bulbs, has a nice white with a hint of blue, and your ballast will drive it perfectly.

If it were me, I would put the T5's in first, then change the MH bulbs. You may find you don't need the 250 watters. The LET T5's will help greatly with the PAR and you can adjust the color so easily with T5 bulb changes. If you decide you still need more PAR, swapping to 250 watt bulbs and ballasts is pretty easy.

thbrewst
01/31/2012, 12:44 PM
Awesome. Many thanks for the guidance!!!