Spectrum shift of the MH bulb

[zhenya]

I'm posting this so others can see how a light bulb can shift spectrum and if you had those for a few month you may not even notice.
This particular bulbs I installed about 4 month ago and the tank looked quite nice, blue-white with the actinic supplimentation. Few days ago I recieved a new set( this time I decided to go with 12K instead of 10K), just because I like to order them new bulbs in advance, so I decided to try one of them to compare what it would look like next to the 10K I already had burning for a few month.
Well, you will not believe your eyes when you see this.



This is a shot from February, you can;t even tell that the lights look this pink in this image, can you? Well look at the first image.

PS. Needless to say, I removed both of the bulbs and installed some old Coralvue 10k bulbs that I never really fired. They were just laying around here doing nothing. The 12K bulbs are going back as well as I found out that the PAR is really miniscule on those.

Here's a shot of the tank with those 10K Coralvue's. I think I like this best. The only problem is this are the bulbs that I had problems with last time I tried them. Hopefully, since this are all new corals, I won;t have any problems.

[Poseidon]

Holy Cow Gene! It looks like a 20K on the left!

[zhenya]

Holy Cow Gene! It looks like a 20K on the left!

Mike, it is actually not that blue at all at 12K. I really liked the color of the bulb if it wasn't for the redicilously low par. I was really trying to show how 10K bulb that is on the right shifted to the red/pink. I was wondering why some of my corals were turning brown in this tank with extremely low nutrients level.

[Ninong]

Gene,

There is little if any information online about how various metal halide lamps degrade over time. Dr. Sanjay Joshi did a very limited analysis of this about eight years ago. For that study, Dr. Joshi asked hobbyists to contribute used 400w metal halide lamps along with a note stating their estimated total time in service.

This was obviously a very unscientific way to go about it but it was better than nothing and it was helpful as far as it went. From that study we learned that metal halide lamps do not degrade at the same rate and, more importantly, some degrade more unevenly across the spectrum than others. The 400w Radium blue lamp (aka 20,000K) at four months is not at all what it was at 100 hours. It is not only weaker, but it's spectral distribution is significantly changed. For that reason, the usual recommendation for people who really like this lamp is that it should be changed at least every 6-9 months.

The 400w lamp that showed the least degradation over time (among the lamps Sanjay tested) was the Iwasaki 6500K.

This reminds me of all the fuss that was made some five or six years ago when the then new ALS Sunburst 14,000K metal halides hit the hobby market. People were switching to them right and left based solely on their "pretty blue" color. Then it turned out that they not only had substanially less PAR than comparable established brand 10,000K lamps but their product quality was questionable as they were failing right and left. The most common "good thing" that was posted about them was that the vendor was most helpful in replacing those lamps that failed during the first three or four months of use.

I guess the best thing to do is just to keep reading the various posts on the boards when someone posts about their great new metal halide discovery. Over time, the various new brands will gain a "reputation" that might give more insight into their worth.

[zhenya]

George,

I remember it very well... I don't know if you remember, about a year or two ago I decided to try then new Coralvue 10K bulbs. If you do remember, you'd remember that my corals nearly all fried under those bulbs. Started to lose tissue and all that good stuff. This 12K Reeflux are very pretty in color, and look very bright, but the PAR values are extremely low. The 400w 12K Reeflux are very nice color bulbs with very acceptable PAR numbers, and I almost went for the 400 watters, but my wife said "no way Jose" to the higher electrisity bill. So, I'm stuck between the Reeflux 10K and the Megachrome bulbs. Not sure what I'm going to do but I need to do something quick to change those Coralvue's, if things turn for the worse.

[kevinpo]

Hi Gene,
I have found the latest Coralvue Reeflux 10,000K bulbs to be quite acceptable. They really pronounce the blues and have a good life span. I run 400W'ers and drive them with PFO HQI ballasts.

Regards,
Kevin

[Poseidon]

I like my 10K XM's Gene, good par, and decent color too.

[zhenya]

Hi Gene,
I have found the latest Coralvue Reeflux 10,000K bulbs to be quite acceptable. They really pronounce the blues and have a good life span. I run 400W'ers and drive them with PFO HQI ballasts.

Regards,
Kevin

Hi Kevin,

I like Reeflux alot and this is what I ran for a year or so. I use 250 watters over my 75g tank and had no issues except that the colors were fading to browns.
So I ordered the 12K Reeflux and coloration of them is really to my liking, and I would keep them if it wasn't for very low PAR. Like I said in my previous post, I wouldn't noticed the pinkish hues of the 10K bulb( which is only about 4 month old, maybe little less) if it wasn't burning next to that 12K bulb. The older Coralvue( not Reeflux) 10K had nice coloration but I removed them as my corals begun to show stress yesterday evening. So I put 8 month old XM 10K I had laying around and will wait untill I get new set of bulbs, either the Reeflux 10K or Megachrome 12K.

Mike, I'm OK with the XM bulbs but my Reeflux 10K coloration were better when they were new.

[Poseidon]

Gene, are those 10K XM's that shifted on you? What ballast are you using?

[zhenya]

Gene, are those 10K XM's that shifted on you? What ballast are you using?

No, Mike. I switched from XM's to Reeflux in 2006, after new years I think. Then in the fall, November I believe, I bought a new set and haven't noticed anything different untill couple of days ago when I tried the 12K and took some pictures because the Reeflux bulb had distinct reddish coloration burning next to the 12K bulb.
I started this thread so people would pay more attention to the bulbs they burning. Sometimes you just can't see the difference after looking at the tank for long time and getting used to the look of it. You know what I mean?
Having said that, how do you check if the spectrum is off?

[kevinpo]

Hi Gene,
Are you using any supplemental lighting? I have been playing around with some 450nm T-5 HO German bulbs for the last few months. They give a interesting color and make some SPS turn very nice colors. I had a couple of cream colored Acropora corals turn a beautiful light teal color.

Regards,
Kevin

[Poseidon]

Sometimes you just can't see the difference after looking at the tank for long time and getting used to the look of it. You know what I mean?
Having said that, how do you check if the spectrum is off?

You are correct, and I am guessing that shift in spectrum happened slowly over time right? Did you just go in the room one day and see the pink?

Here is an option for checking the spectrum, when you get new bulbs you like take a picture, using the K rating that best reproduces what you see. Then you record the K rating, and write it on the back of a printed picture. After a month or 2 do the same, but from this point on you have to use the K rating from the first image, if the images match, then no shift. Easy huh?

[zhenya]

Hi Gene,
Are you using any supplemental lighting? I have been playing around with some 450nm T-5 HO German bulbs for the last few months. They give a interesting color and make some SPS turn very nice colors. I had a couple of cream colored Acropora corals turn a beautiful light teal color.

Regards,
Kevin

Kevin,
I use two VHO bulbs, actinics, to supplement 10K bulbs. Without them the lighting is just too yellow for my liking. As soon as it gets warmer around here I will be making a new canopy that will have two Lumenarcs in it and I plan on changing those VHO's for the T5's. It will also have two moonlights for night viewing.

[kevinpo]

Hi Gene,
I used the same ballast to drive the T-5's I just replaced the end caps. The T-5's have individual reflectors that snap onto the bulbs. They really make a big difference. I will be replacing most my VHO's (28) as funds allow

Regards,
Kevin

[Papa Doug]

Gene, That looks identical to the 400w 12K Sunburst bulbs I use to run or the Radium 20K when driven on a normal ballast.

I have friends running the Coralvue 14K bulbs on normals and they look pretty good.

[zhenya]

Hi Gene,
I used the same ballast to drive the T-5's I just replaced the end caps. The T-5's have individual reflectors that snap onto the bulbs. They really make a big difference. I will be replacing most my VHO's (28) as funds allow

Regards,
Kevin

I plan on using the same ballast as well to drive couple of T5 bulbs. I already ordered reflectors and end caps and should be getting them soon.
Good luck on swaping all those VHO's, that sounds like a huge job to me.

Hi Doug,
Nice to hear from you!
I really like those 12K bulbs but a 250w version has pathetic PAR, so I have to either switch to the 400w or go with different Kelvin number bulb. I figured I would either stick with the Reeflux 10K's or go to Megachrome German bulbs. I'm waiting for Jeremy from PA to call me tomorrow so I can make my decision. Will post pictures as soon as I get new bulbs, hopefully my corals survive 'till then... ;)

[Papa Doug]

Hi Gene,
Are you using any supplemental lighting? I have been playing around with some 450nm T-5 HO German bulbs for the last few months. They give a interesting color and make some SPS turn very nice colors. I had a couple of cream colored Acropora corals turn a beautiful light teal color.
Regards,
Kevin

Would that be Giesemann? I have two kinds of actinics. One called actinic + and the other pure actinic. The first is a much brighter blue colour with the latter being very similar to the Philips actinics we used.

[kevinpo]

Would that be Giesemann?

Hi Doug,
Yes that is correct. It's the actinic+ 450nm very blue bulb.

Regards,
Kevin

[zhenya]

The older Coralvue( not Reeflux) 10K had nice coloration but I removed them as my corals begun to show stress yesterday evening. So I put 8 month old XM 10K I had laying around and will wait untill I get new set of bulbs, either the Reeflux 10K or Megachrome 12K.

Well,scratch that statement. Those old Coralvue 10K bulbs are back on as of this morning. Friend of mine stoped by and we raised canopy a bit and I put them back on because the Reeflux 10K and old XM's just looked terrible. Plus, on top of the ugly looks, my corals looked really pitiful this morning.

For now everything looks real nice and coloration on some pieces is returning to normal. I had most of the corals turning brown and I didn;t realized that it was the bad bulbs.

[zhenya]

I think I need to update this thread with new information about the new bulbs.
I recieved my Megachrome 14.5K bulbs the other day and installed them to replace my Coralvue's because I noticed the same reaction from corals that happened in 2004 when I tried them. Anyway, I like this Megachrome bulbs and believe it or not they appear whiter than some of the 10K I tried in the past.
Here's the picture, see for yourself.