Hello Al, long time no see...

[hahnmeister]

Hello Al, been a long time since I have seen you at a WRS meeting. I bought a Quantum meter alot like the one you have and have been conducting a similar test, as well as a 'Red Tide' Radiospectrometer to see the spectrum shift. I have been comparing the outputs of pheonix bulbs running on a PFO HQI ballast for one year, and on the the Icecap ballasts. I didnt think I had enough of a control group (not enough bulbs to declare anything... only 2 HQI running bulbs, and 2 IC bulbs), so I havent posted anything, but I did see these trends...

The Icecap ran the bulbs into the ground faster than the HQI. Granted, the Icecap has a lower output to begin with, but also over time, the Icecap degrades more than the HQI. This contradicts the claims that the e-ballast can make this bulb run longer. After one year, 8 hours per day on a timer, on the IC ballast, the pheonix bulbs were only retaining about 65% of their output. They also looked like 20,000K bulbs... very monochromatic blue.

The PFO HQI ballast ran the bulbs much brighter, and slightly whiter, but after a year of running 8 hours per day, still kept about 85% of its output! After a year, the bulbs looked whiter as well: no yellow tint, but they do look more daylight like a true 14,000K... not bad really.

Granted, the spectral shift of the HQI may account for some of the greater PAR reading on the HQI ballast, but maybe 5% as Dana Riddle's experiments showed with an old XM 20,000K. The M80 ballast seems to be the better ballast here.

It would seem that Icecap's claim that the 'higher frequency' doesnt apply to HQI bulbs. While Im sure their technology maintains SE/probe start bulbs much better than a magnetic ballast, it isnt enough to keep the DE bulbs from degrading, or being 'underpowered'. The lower output of the IC (compared to M80) running DE bulbs should be proof enough, as if a higher frequency is supposed to make up for lower wattage to the bulb, then the output should be the same, no? Otherwise, an underpowered halide would end up with some of its contents burning into the quartz because it doesnt get excited enough, causing the potential output from those gasses to be lost, as well as blocking the output from the remaining gasses. I mean, if a higher frequency is supposed to make up for less power, then we should see just as many photons from a HQI run bulb as a IC one, right?

[ReeferAl]

<a href=showthread.php?s=&postid=9661900#post9661900 target=_blank>Originally posted</a> by hahnmeister
After one year, 8 hours per day on a timer, on the IC ballast, the pheonix bulbs were only retaining about 65% of their output.

It's interesting that your 2 Phoenix bulbs had only 65% of their original output after a year while all mine had about 75%. I assume your IC ballasts are the "new" style. The original IC MH ballasts had some problems. Unless yours were bought over about 4 or 5 years ago they should be the new ones. If these are the same ballasts it suggests that operating conditions may well play a significant role in MH bulb degradation. My lights are all in Reef Optix III reflectors. What reflectors are you using?


The PFO HQI ballast ran the bulbs much brighter, and slightly whiter, but after a year of running 8 hours per day, still kept about 85% of its output! After a year, the bulbs looked whiter as well: no yellow tint, but they do look more daylight like a true 14,000K... not bad really.


Were these in the same reflectors as the bulbs on the IC ballasts? If the reflectors were the same it would suggest that the bulbs will last longer on an "HQI" ballast over an IC electronic.

The lower output of the IC (compared to M80) running DE bulbs should be proof enough, as if a higher frequency is supposed to make up for lower wattage to the bulb, then the output should be the same, no? Otherwise, an underpowered halide would end up with some of its contents burning into the quartz because it doesnt get excited enough, causing the potential output from those gasses to be lost, as well as blocking the output from the remaining gasses. I mean, if a higher frequency is supposed to make up for less power, then we should see just as many photons from a HQI run bulb as a IC one, right?

I don't know enough about the engineering principles behind MH bulb and ballast function to confirm your speculations about high frequency ballasts etc. I don't know if the high frequency alone will necessarily make the output of the bulb the same as with the standard, non-electronic ballast. There may well be other factors coming into play. OTOH, it is frequently said that relative "overdriving" of a bulb will make it burn out sooner and slight "under driving" will help it last longer. Your results would lead one to question that claim.

Allen

[hahnmeister]

1st paragraph: Yes, my IC ballasts are the newer style. As for reflectors, I do use the dreaded PFO mini-pendants due to their size, but my results were not taken with a reflector. I made a test bench, er, black box much like sanjay uses. Its a 2' plywood cube painted black inside with a 250wattDE socket, and a mounting frame for the Tempered LoE glass which I borrow from one of the PFO's. The tests are best done w/o a reflector, as Im sure you are well aware... the positioning of the sensor under the bulbs can vary the output readings of the bulbs wildly depending on how the reflector's fascets converge the light. I didnt want to say it, as I believe your readings overall are pretty close to what I was getting, but to test the bulb output over time with a reflector makes it hard to be sure of the accuracy because a slight change in sensor positioning can change the results. The reflector changes the distribution of the light from a pure point source. Perhaps this is why your readings were slightly higher than mine... maybe the sensor happened to be under more of a 'hot spot' for the more recent readings?

2nd paragraph: no reflectors... just pure point sources in the 'black box'. Having the sensor 2' away prevents optical problems as well (even without reflectors, the bulb still has certain 'hot spots' just from its own glass... so to eliminate this, taking readings from 2' away helps.

3rd paragraph: you said, ...'and slight "under driving" will help it last longer'... This is not true. Underdriving is just as damaging if not worse than overdriving. The bulb's contents dont fully excite, so some of the contents just sits in the bulb, not giving off photons. While in this state, they burn into the wall of the tube... so you arent only losing the output from those atoms, but also blocking the output from the atoms that are excited because those elements are blocking the output. This is why I have taken PaulErik's advice to heart, and only run HQI rated ballasts with HQI rated bulbs. He is the one who first told me about the dangers of underdriving.

On a side note: Your reflectors could be swapped out for something more like a lumenarc DE, and you would see better penetration into the water than what you currently have. That target range of 400-500 is right on the money from what I have seen as well (havent seen anything that can even tolerate much more than 500), and many people are doing well with high-light corals under much less. I would almost extend that 'high-light' category to be as low as 300, as long as the coverage of the light is over more of the coral tissue. I have seen high-light milliporas color in better/grow faster under T5s in the 300 range that other wise needed light in the 500 range with halides, and I can only attribute this to the T5s being able to hit more of the coral's surface with light because they are more spread out as a source.

Here, I have been taking photos and then combining the light levels from the meter into composites at the WRS forums...
http://www.wisconsinreefsociety.org/...topic.php?t=87

http://www.wisconsinreefsociety.org/...topic.php?t=41

http://www.wisconsinreefsociety.org/...topic.php?t=44

You might recognize a couple there...lol. The results have been very informative, and provided people with exact info on how to better their systems. The meter for $318 was money well spent. Its given me more useful info than the $1200 spectrometer has at least... so far.

[ReeferAl]

by hahnmeister
As for reflectors, I do use the dreaded PFO mini-pendants due to their size, but my results were not taken with a reflector. far.

You missed my point. You are running your bulbs in a different reflector, a smaller one. This results in a different operating environment that may be causing the bulbs to lose output faster than they do in my setup with RO III reflectors. Your output falls to 65% of original in 1 year while my output with the same bulbs, same ballasts, same photoperiod, but different reflectors falls only to 75% in 1 year. That suggests that the PFO mini reflectors may be causing premature wearing out of the bulbs.

As far as the measurements I am getting, a comparison with the measurements from someone else is meaningless. As you say, mine were measured in the reflector, not separately. Most important however is that the distance of the light meter's receptor from the bulb is undoubtedly different between my measurements and those of anyone else. My measurements were taken about 7 in from the glass of the reflector, which would be even further from the bulb itself.

The measurements I obtained are not really that relevant by themselves. It is the percentage of original light output over time that was the important point. For example, I could have had measurements twice what I had if I had made the probe holder shorter.

to test the bulb output over time with a reflector makes it hard to be sure of the accuracy because a slight change in sensor positioning can change the results

That is true, but as I mentioned in the article, with the probe holder I built, I was able to get reproducible measurements that varied by less than 1%. The holder gave me a consistent distance and then with each measurement I "fished around" with the probe holder for the highest value I could find. This eliminated the requirement of knowing the precise position of the probe for each measurement. Incidentally I would note that it was not always directly under the center of the bulb.

Allen

[hahnmeister]

As far as the fixture changing the bulbs... I dont know about that. Halides arent vulnerable to heat buildup like phosphor based bulbs. I have a hard time believing that its the pendant, or any pendant for that matter.

Sure, I get that its relative... I took my own values from the beginning, after the bulbs were running 100 hours, and then after 12 months. Im only comparing my percentages to your percentages.

I dont think our tests are that far off really. On a tangent, but possible clue, how long did you 'burn in' the bulbs before getting your initial values? I ran mine for 100 hours before testing.

Im not disputing your results... I came up with 65% after a year, and you came up with 75%... thats not such a huge difference considering the time frame and how the reflectors may vary the peak values. I should also note that not all of the bulbs were running constantly at the time of evaluation. I had one set of Icecap pheonix bulbs running for a year, then on the shelf for a year while I waited for the HQI group to 'mature'. Its entirely possible that this extra 'shelf life' robbed them of some output.

I suppose now I have to burn a HQI and a Icecap side by side for the next test! Lol.

Anyways, I think what I was trying to say was that while you may experience a 25% loss in one year, I, as well as a few others, have experienced less with HQI/M80 ballasts.

[ReeferAl]

Anyways, I think what I was trying to say was that while you may experience a 25% loss in one year, I, as well as a few others, have experienced less with HQI/M80 ballasts.

I agree, your experience does suggest that. It is an interesting finding and it would be useful to have more side-to-side comparisons to see if it really holds true. I'm not necessarily a proponent of electronic ballasts. They're just what I happen to have. Frankly, I don't know that they live up to all their hype, but that is another issue.

Maybe when it's time to replace my bulbs I'll spring for 3 HQI ballasts and compare 4 bulbs on IC ballasts to 3 on HQI over a year.

Allen

[seandanekind]

Hey Al-

Awesome job on the article. It's nice to finally have some complete data tracking lamps from burn in to a solid year later...

You got me to dig and find my old thread from a year ago where I compared old Phoenix lamps to brand new ones and you mentined starting your study:
http://archive.reefcentral.com/forum...hreadid=787010

I'll measure mine this weekend since it's been another solid year, and I never did replace the other 2 bulbs (I'm getting ready for 400W Radiums), so they're over 6000 hours each. That might give you a little more data to play with. I didn't do any monthly readings, but hopefully I'll see something similar to your 6-9% difference in the extended use for my 2 older lamps.

I have visually compared the spectrum of newer lamps a few months back (over my frag tank) and the only spectral difference I can see with my eyes is the same difference I noticed in my thread from a year ago... where it looks like the actinic "pop" has faded (I assume that's the tiny little bump around 420nm fading away).

...and I still need to send those lamps to Sanjay...

[ReeferAl]

I'll be looking forward to your measurements. Have these been running on Ice Caps or the M80 ballasts?
Allen

[seandanekind]

M-80's - in ReefOptixIII's. I should be able to get the measurements by Saturday evening.

[seandanekind]

OK, new data:

The PAR readings are the highest I could get spending about 2-3 minutes per fixture searching for the max value while maintaining the same 7" distance as before. Lamps A and D are the 2 that I replaced 14 months ago

Lamp A + Clean Glass = 915 PPFD
(appx 3400 hours for 425 starts)

Lamp B + Salty Glass = 810 PPFD
(appx 6400 hours for 800 starts)

Lamp C + Salty Glass = 890 PPFD
(appx 6400 hours for 800 starts)

Lamp D + Clean Glass = 1015 PPFD
(appx 3400 hours for 425 starts)


Taking my original data from 14 months ago...
http://archive.reefcentral.com/forum...hreadid=787010

So here are the percentages of PAR level retained after 14 months (appx 3400 hours for 425 starts):
A 915/1350 = 68%
B 810/1100 = 74%
C 890/1250 = 71%
D 1015/1450 = 70%

So roughly, all of these lamps are giving about 70% of the output they gave 14 months ago.

Assuming from my earlier measurement that these lamps (+reflector+ballast) are averaging 1400 PAR brand new, the 2 older lamps have retained 57% and 63% of their original output after more than 2 years.

So I'm seeing a 30% drop from the original PAR level in the first year (actually 14 months), and about another 10% drop from the original level the second year. I'd say that's pretty close to what Al found...

It's hard for me to be sure on the 2nd year since I never really got the initial measurement when those lamps first went into service. You can work the stats to show a 15% or 20% drop in the 2nd year if you really play with the numbers.

[ReeferAl]

<a href=showthread.php?s=&postid=9732249#post9732249 target=_blank>Originally posted</a> by seandanekind

So I'm seeing a 30% drop from the original PAR level in the first year (actually 14 months), and about another 10% drop from the original level the second year. I'd say that's pretty close to what Al found...

Looks good. Really not too bad a drop-off IMO. Now the question is, what does the spectrum do over that time? We'll have to wait on that question.

From some rough measurements I did, the power consumption doesn't fall off much if at all as the light output declines. Obviously there will come a point at which the decline in efficiency makes it worth replacing the bulbs just for the electrical savings. That will depend on what you pay for electricity though. I tried to do a calculation to determine how you could decide when that time would be. There was a time when I could have figured that out pretty easily, but my math ability isn't what it used to be. Maybe I'll give the question some more thought if I have insomnia some night.

Allen