Lighting Website Updates

[Sanjay]

Originally posted by The Grim Reefer
Well what do you want first, 150 or 175 watts? I got plenty of time to do the grunt work of finding what's out there if that gives you more time to buy and test the stuff

Lets go with the 175W since those are the ones I have the least amount of data on.

sanjay.

[Herbert T. Kornfeld]

I think most would be more interested in 150s rather than 175s. Esp the classic blue radiums that for some reason cant be found in a 250wattDE.

[Sanjay]

There is quite a bit of data on the 150W DE lamps, including the radium on my website.

sanjay.

[armygreen11]

Sanjay- First, I'd just like to say thanks for all the time and effort you've put into the testing of all the MH reef lighting you have documented over the years. I know it serves as a very important knowledge base for anyone interested in trying to create an optimal reef environment.

I heard you presented data on different bulbs' spectrum changes over time. A friend of mine in CMAS (Maryland) attended the presentation you gave the same day as Steve Tyree and said that you showed data proving that some 20K bulbs lose most of their PAR after a few months of use because most of their light output is concentrated in the narrow spectrum 440-460nm range and this large "spike" falls off very quickly, while 10K bulbs are more full spectrum and maintain a higher level of PAR over a longer period.

I would definately like to learn more on this subject. I would really like to know how long bulbs really "last", and which bulbs provide the highest CCT with the least loss of PAR over time. I personally really like the look of 20K bulbs (especially the XM's) but I don't want to lose most of my avalible light a few months after installing them.

[denvig]

Has anyone done a study of which 250W DE bulb holds its color spectrum the longest? (Longest lasting usable light)

[Sanjay]

To do this right would take a lot of effort and coordination. But we could get some estimates of what the light output is from lamps after they have been used. I am gradually collecting data from used lamps sent to me by hobbiest, so at least I will have some information on what the is final par of these lamps (not knowing the initial par).

sanjay.

[Herbert T. Kornfeld]

Im going on 18 months with my Aqualine 10,000Ks...they seem to be holding spectrum just fine.

[Sanjay]

if anone is interested in sending me thier used lamps, I can measure the PPFD and at least we will have some idea of what the values are when people are changing them out.

sanjay.

[FastUno]

Sanjay, I know this one may be a tough one to answer, but here it goes.

I am in a situation where I will have a glass shield on a SE MH set & expect to loose some 15-20% of pars. The only advantage I have to combat the loss is that the fixtures will be directly on top of the tank, as opposed to the normal 6-8 inches above the tank that we see. How much more pars do you think are gained by having the MH directly above the tank?

When you perform your plot tests, how far away from the bulb do you normally take your measurements?

[Sanjay]

Having your light closer to the water surface will help. How much is hard to quantify, especially since you will be increasing peak values, but also changing the spread. If you still get good spread in the tank, then lowering the lights will definately compensate for the loss due to the glass shield.

For the lamp data, the distance that I have used for all tests is 18". For the reflector data, the measurements were at 6", 9" and 12".

sanjay.

[Travis]

FastUno, is the 15-20% loss just a guesstimate? I am just curious because I use a 1/4" glass (regular glass) shield during the summer months to help keep the tank cooler. I searched for a while before I decided on the shield but I never came across any data that showed what the true losses would be with any type of lens.

[The Grim Reefer]

I just measured my actinics with and without the glass top, just a tad over 20% loss.

[Sanjay]

Travis:

I measured losses ranging from about 18-22% with the glass shield. The losses are higher at the blue end of the spectrum as expected.

sanjay.

[FastUno]

My numbers are from estimates from reports such as Grim's & Sanjay's. For those who have tested with shield, how thick was the glass shield & does the same apply for acrylic? I would think the thickness & the composition of the glass/acrylic should make a difference.

I am sure this adds another layer of complication in terms of quantification. I am also sure that the position of the shield relative to the bulbs also makes a difference in the refraction of light & thus the spectral & par outputs.

Sanjay, your tests are done with the probe exposed to air, or actually in the water?

[Travis]

I'm also curious as to what thickness the glass was in the testing.

FastUno, I personally wouldn't recommend using an acrylic shield. That is what I tried initially. People told me it would warp due to the heat from the bulbs but I thought my design would prevent that as I'm exhausting most of the heat outside. Sure enough, the acrylic warped big time in about a month. Of course, it was only 1/8" thick, but I think even 1/4" would warp pretty fast. I'm sure it would allow better light penetration but at a higher cost due to the need to keep replacing it.

Has anyone performed tests with different types of materials such as glass vs. low iron glass vs. acrylic to see what the differences in light penetration are?

[FastUno]

I have a T5 setup with an acrylic shield & was wondering how much light I was losing with it on? I also get a slight warp effect at the edges of my fixtures, but nothing major. I could only imagine the effects of acrylic under a MH sys.

Sanjay, have you done any tests with T5's? If so any links or posts?

[Sanjay]

I have done one test with T5s, and am currently waiting on a fixture from Sunlight Supply.

sanjay.

[The Grim Reefer]

Accurate T5 data in the works? Cool!

[Herbert T. Kornfeld]

70watt halides, 1000watt halides...whats next? I would be interested in 1000watt halides because things seem to change alot at that level...just like how cheap hamilton 14,000K bulbs have horrible PARs compared to an Aqualine 10,000K at the 250watt level...but best them in the 400watt level. The hamilton 14,000K is half the price of many other 1000watt bulbs...10,000K and 20,000K...I wonder how it does. It seems like the outputs of bulbs at that level change a bit as well...20,000K bulbs seem whiter at 1000watts, 14,000Ks look like 10,000Ks, etc.

[Sanjay]

Yeah.. i could keep busy for several years just testing all the MHs and trying to address the issues.

Right now I am more interested in figuring out a nice way to get the reflector data on the web.

sanjay

[Sanjay]

Originally posted by The Grim Reefer
Accurate T5 data in the works? Cool!

I thought you already had good data on the T5s. !!

sanjay.

[The Grim Reefer]

Hey, I get my arms wet and scare the crap out of my fish when I do readings No substitute for your precise readings but I guess they do some good. I am sure SLS hates my guts after the reflector readings I posted

[RedEyeReef]

Originally posted by The Grim Reefer
Hey, I get my arms wet and scare the crap out of my fish when I do readings No substitute for your precise readings but I guess they do some good. I am sure SLS hates my guts after the reflector readings I posted

Do you have a link to this data?

[The Grim Reefer]

It is a thread in the equipment forum in the thread "the great T5 glarathon".

[Herbert T. Kornfeld]

Sanjay, 2 Qs...

One, I thought you tested the hamilton 250 - 14,000Ks in the DE version as well...they arent on the site...???

Also, in late Sept, Penn State is having some big meeting on china<<