Lighting tests

[StirCrazy]

Well now that I have a MH bulb I can do some comparisons between MH and PC lighting. I was quite surprised in what I found and I am sure some of you will be also...

First off the line up, I am running a 10000K, 96 watt PC (this is the one I am testing) and a 175 watt Ushio 10000K MH. For positioning I placed the PAR sensor 9" below the bulb (in the water) I would have gone 12" but the design of my sensor mounting prevented me from doing that. it also prevented me from getting directly under the MH bulb, so I suspect when I redo this test when I make a new mount the MH #'s will be a little higher.

So to get an idea of where the sensor was in relation to the lights...
1, 9 inches directly below the PC and
2, 9 inches below and 4 inches to the left from the MH.

With just the PC on I got a score of 192.75 PAR (150 PAR is considered the minimum for SPS)

with Just the MH on I got a score of 255.35 PAR(I suspect this will be between 300 and 350 when I retest)

with Both on I get a score of 447.18 PAR

a couple interesting (or maybe not) tidbits, the MH is 1.8 X the wattage of the MH, but the light is only 1.3 X more (even if we assume 325 for a new score on the second test it will be 1.68 X )
this shows that the PC is more efficient than a MH per rated watt.

Just thought I would throw this all out for anyone who is interested...

Steve

[ 21 August 2002, 19:03: Message edited by: StirCrazy ]

[Aquattro]

Steve, nobody is interested. PC bulbs are inferior bulbs. I would say you need a new light meter. Also, if you get rid of the rest of those PCs, you'll have room for real lights. hehehe

[StirCrazy]

Originally posted by StirCrazy:

Just thought I would throw this all out for anyone who is interested...

Steve

<font size="2" face="Verdana, Helvetica, sans-serif">sorry this should have read

"Just thought I would throw this all out for anyone who is interested... and has something intelligent to say"
:D :D

Steve

[Aquattro]

Well, sheeesh!! You should have said that in the first place!! I thought you were bored and wanted to argue.

[StirCrazy]

ohhh.. man.. what a cheep shot LOL....
I almost spit diet coke on the moniter :D : D

Steve

[Aquattro]

[img]tongue.gif[/img]

[reefburnaby]

Hi,

I though Steve wanted to stir up something to bring up his posting count [img]smile.gif[/img]

Back to this thread...I am not surprised with your results. IMHO, the extra heat given off by the MH is usually the wasted power.

Cool though...

- Victor.

[Doug]

Interesting Steve, but thats at 9 inchs. Halides are supposed to penetrate deeper than vho or pc bulbs, thus the reasoning for their use on deeper tanks.

In a shallow tank, one could grow sps with normal outputs bulbs. Can you do a measure, say at 18 inch and one at 24 inch? That would be interesting.

Also a bulb cost versus intensity versus watts, would be interesting also. Halide fixtures to drive 175 watt halides can be pretty cheap now days and the bulbs can be purchased for a $100 on sale. I have never purchased pc bulbs or fixtures, so cant comment on them.

175 watt German 10K bulbs are one of the best on the market. They dont necc. need any supplement actinics. I was going to run mine the suggested 18 months before changing out. It would also be good to see the par ratings at different depths, compared with pc,s after a years use. Do pc bulbs still have good colour and par after a year?

[ 22 August 2002, 06:01: Message edited by: Doug ]

[StirCrazy]

Originally posted by Doug:
Interesting Steve, but thats at 9 inchs. Halides are supposed to penetrate deeper than vho or pc bulbs, thus the reasoning for their use on deeper tanks.

In a shallow tank, one could grow sps with normal outputs bulbs. Can you do a measure, say at 18 inch and one at 24 inch? That would be interesting.

Also a bulb cost versus intensity versus watts, would be interesting also. Halide fixtures to drive 175 watt halides can be pretty cheap now days and the bulbs can be purchased for a $100 on sale. I have never purchased pc bulbs or fixtures, so cant comment on them.

175 watt German 10K bulbs are one of the best on the market. They dont necc. need any supplement actinics. I was going to run mine the suggested 18 months before changing out. It would also be good to see the par ratings at different depths, compared with pc,s after a years use. Do pc bulbs still have good colour and par after a year?

<font size="2" face="Verdana, Helvetica, sans-serif">Doug, I plan on doing a test every month to compare. the reason I did 9" this time is that I only have one mounting stick for the PAR sensor and with the angle it is bent, it was a distance of 9" to keep it strait up and down. I am going to make a couple more sticks so I can do different depths and get more under the MH bulb. the problem will be as I only have one MH bulb and it is directly over my rock pile so I don't know if I can go much deeper unless I buy another bulb... even with another bulb the most I could do is 19 to 20" as I have a 24" deep tank and a 6" sand bed but i will see what I can come up with.

the cheepest you can do a 175 watt Ushio MH is 129.00 for the bulb and if I go buy the ballast my self... 69.00 and then a few bucks for wiring.. for a PC set up I can get TWO 96 wattt bulbs for 129.00 and a WH7 ballast for 58.00 plus a bit for the wiring.

Steve

[reefburnaby]

Hi,

Since the measurements were made with an offset of 4" away from the MH bulb, the MH can still drive a bit more light power in to a small area than a PC. I suspect that at 18" in depth, that bright area would cover the width of the tank.

In general, MHs run at around 50 to 60 lumens per watt and PCs run at 80 to 92 lumens per watt (from GE lighting). So, PCs are more efficent light sources. But it is harder for PCs to focus light in to a box than a halide. If you can solve that question, then PCs do have a slight advantage over MH.

Hmm...maybe I should get one of those PAR meters....always wanted to know what my overdrives are doing.

- Victor.