When to REALLY replace Metal Halides

mobyreef · 11/28/2010, 09:53 PM

I have read, and pretty much understand, par as a measurement to determine photo synthetically active radiation, But... I don't have a par meter.
I DO have a photographic light meter which doesn't read par but does read brightness ect. I also have a color temperature meter that I have on-order (It's old but Cheap). Is there any way to use my photography light meter to determine when my metal halides are Really needing to be replaced? When I get my color temperature meter I will see if the 14k bulbs are still 14k. Am I missing something about par? Is it a meter I really should be using? I noticed that Marine Depo & Bulk reef supply don't carry them in stock. Where can I one buy one? I just hate to throw away a bulb that still fires and still looks blue after a year of use just because they say to replace them every 8 to 12 months! Any enlightenment on the subject will help and possibly save me some coin as well.

Thanks for any help.

turbosek · 11/28/2010, 10:42 PM

I agree. I am following to see what others say. I am coming up on 7 months on my 3 400W. This is my first reef tank. I want to buy a PAR meter so I can monitor my next set of bulbs.

mobyreef · 12/04/2010, 10:57 PM

I posted this in the General threads for anyone who is interested in following it there. Maybe it will get a better response?

badguitarist · 12/05/2010, 02:45 AM

as far as getting a PAR meter goes. look up Apogee Par meters in your favorite search engine, they are somewhat of an industry standard. I will also say I don't replace my bulbs every 8-12 months but more like every 2-2 1/2 years. some I'm sure would disagree with this but thats just how I do it. I have no light meter to give factual data with but bulbs dimming over time is evidenced when a new bulb is put in and corals and or coraline algae bleach. be very careful when replacing bulbs, address this issue

mobyreef · 12/05/2010, 09:19 PM

I got my color temperature meter and checked my lights. The one XM 15k, which is a 1 month old bulb, reads at about 16k and the two older (10 to 12 months) XM 10k bulbs are reading at 7 & 8k. Just fyi I was experimenting with what color temp. bulbs I wanted for the system so I have one 15k in the center and 10Ks on each end of my 150g. I need to replace the 10Ks and will probably do so with 15Ks. In my research of par meters and bulbs I have learned that the color temperature of the bulbs will decrease with bulb life and so I will probably just use the color temperature meter I got off of eBay for 30 bucks and monitor the degrees kelvin of my bulbs. If anyone else is interested in getting their own color temp meter I have seen these meters go from 25 to 70.00 on eBay. Do a search for Gossen Sixtycolor color temperature meter. It is an old analog meter but it works great I have tested it with known bulbs (tungsten is 3200K) and the readings are accurate.

Happy Reefing!!!

PS. I may try Radium bulbs next... any thoughts? I bought the XMs because I've read that they have the highest par ratings.

11/28/2010, 09:53 PM	#1
mobyreef Registered Member Join Date: Oct 2010 Location: Louisville KY Posts: 43	When to REALLY replace Metal Halides I have read, and pretty much understand, par as a measurement to determine photo synthetically active radiation, But... I don't have a par meter. I DO have a photographic light meter which doesn't read par but does read brightness ect. I also have a color temperature meter that I have on-order (It's old but Cheap). Is there any way to use my photography light meter to determine when my metal halides are Really needing to be replaced? When I get my color temperature meter I will see if the 14k bulbs are still 14k. Am I missing something about par? Is it a meter I really should be using? I noticed that Marine Depo & Bulk reef supply don't carry them in stock. Where can I one buy one? I just hate to throw away a bulb that still fires and still looks blue after a year of use just because they say to replace them every 8 to 12 months! Any enlightenment on the subject will help and possibly save me some coin as well. Thanks for any help.

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11/28/2010, 10:42 PM	#2
turbosek Registered Member Join Date: Apr 2010 Location: Bellingham, Wa Posts: 48	I agree. I am following to see what others say. I am coming up on 7 months on my 3 400W. This is my first reef tank. I want to buy a PAR meter so I can monitor my next set of bulbs.

12/04/2010, 10:57 PM	#3
mobyreef Registered Member Join Date: Oct 2010 Location: Louisville KY Posts: 43	I posted this in the General threads for anyone who is interested in following it there. Maybe it will get a better response?

12/05/2010, 02:45 AM	#4
badguitarist Registered Member Join Date: Feb 2003 Location: corvallis oregon Posts: 285	as far as getting a PAR meter goes. look up Apogee Par meters in your favorite search engine, they are somewhat of an industry standard. I will also say I don't replace my bulbs every 8-12 months but more like every 2-2 1/2 years. some I'm sure would disagree with this but thats just how I do it. I have no light meter to give factual data with but bulbs dimming over time is evidenced when a new bulb is put in and corals and or coraline algae bleach. be very careful when replacing bulbs, address this issue

12/05/2010, 09:19 PM	#5
mobyreef Registered Member Join Date: Oct 2010 Location: Louisville KY Posts: 43	I got my color temperature meter and checked my lights. The one XM 15k, which is a 1 month old bulb, reads at about 16k and the two older (10 to 12 months) XM 10k bulbs are reading at 7 & 8k. Just fyi I was experimenting with what color temp. bulbs I wanted for the system so I have one 15k in the center and 10Ks on each end of my 150g. I need to replace the 10Ks and will probably do so with 15Ks. In my research of par meters and bulbs I have learned that the color temperature of the bulbs will decrease with bulb life and so I will probably just use the color temperature meter I got off of eBay for 30 bucks and monitor the degrees kelvin of my bulbs. If anyone else is interested in getting their own color temp meter I have seen these meters go from 25 to 70.00 on eBay. Do a search for Gossen Sixtycolor color temperature meter. It is an old analog meter but it works great I have tested it with known bulbs (tungsten is 3200K) and the readings are accurate. Happy Reefing!!! PS. I may try Radium bulbs next... any thoughts? I bought the XMs because I've read that they have the highest par ratings.