Replace MH bulbs every year?

[andy]

Maybe not...

[Chief]

Interesting stuff. Can't wait to see more studies.

 

Jay

[reef165]

well i can say that my bulbs are 2 years old now ( do to funding) they are 400watt 10K ushio bulbs and ive also got 4 140watt VHO the same age and all my corals are growing just fine my only thought is that the VHO's gotta be replaced because the collor on some of the corals are starting to fade in collor a little. Rosecity aquarium and Twidderbait were just at my place looking at my tank maybe one of them could coment on what they saw?

[reef165]

to add, the VHO's are actinic and the MH are mougle base.

[CCR]

I know that you can "see" a change in the XM bulbs in about 3 to 4 months. I'm not sure how much of an effect it has on the growth. I have run my bulbs over a year at a time. What the readings of his test means is really hard to tell. For example a 98% rejection on a ro membrane is twice that of a 96% . So if the out put is lessened by 20% of the original light reading, what is the factor of par to K to intensity? What would the effect be running an HQI ballast to a standard be. I know I would like the electronic, dimming, running at 200 cycle. Just thoughts. Then again looking at Garf setup all under VHO's it's all hard to tell:)

[reefcam]

Just to add to this... many of you know me, but there are many names I haven't seen. So this is info from the past.

 

The reason why MH bulbs are recommended to be replaced every 10 - 12 months is because of the color spectrum. Take a 10K bulb for example. When they are new, the color spectrum will have peak spectrum around the blue range. As the bulb ages, the blue spectrum peak reduces and the yellow to red spectrum starts to rise. Eventually, the 10K bulb will have peak ranges in the yellow to red spectrum, which is ideal for algae growth, as the sun's color spectrum is more towards yellow to red, or your 6500K bulbs. Aside from the color shift, the bulb intensity also reduces with age.

 

The bulb will run for years without going out, and for most tanks, especially ones with SPS, you will notice change in coloration and polyp extension.

 

To your eyes, they will look fine, but under a spectrometer, it will look different. As a previous SPS grower, I replaced my MH bulbs every 10 - 12 months. Many serious SPS keepers also replace their bulbs after 10 - 12 months as well, because of the color spectrum shift.

 

Not sure if the article is still on Reef Central, but search for it.

 

Cheers,

Jim

[reefcam]

just read the article from andy's link and interesting enough, he only tested the PAR rating, but didn't check the color spectrum to see if there's a shift in the color spectrum. Maybe I missed it in my quick skimming. If PAR is all you are looking for, then buy a 6500K 400W bulb and you can run that for many many years. It already lacks the blue spectrum.