MH question

[siskiou]

How long is a MH bulb good for if you run it 5-6 hrs a day?

 

I always hear about 6 months usable life span, but how many hours a day does that number relate to?

[andy]

http://www.reefkeeping.com/issues/2007-04/ac/index.php

 

The people who are telling you to replace your bulbs are the ones selling you the bulbs in the first place -- kind'a like Jiffy Lube insisting on 3500 miles between oil changes, or DeBeers telling you how many months salary to spend on an engagement ring (laugh)

 

For most cases, 12 - 18 months seems to be a good rule of thumb.

[spectra]

Yes I have heard 12 months is a good time to change also.

[siskiou]

Wow! So, the 6 months lifespan isn't actually based on tests, but just a sales pitch?

[CCR]

especially for such a short daily use.

[andy]

Yup, and the data in the article suggests 18 months rather than 12.

[Michael7979]

So this is just for DE bulbs?

 

I just skimmed the article.........

 

Wonder if SE are the same or even close?

[andy]

I expect they're pretty darned close, with SE bulbs lasting even longer given their lower power consumption.

[Michael7979]

I expect they're pretty darned close' date=' with SE bulbs lasting even longer given their lower power consumption.[/quote']

 

Unless you push them with HQI ballasts.

[andy]

Then you're at the same point you'd be with DE.

[downhill_biker]

why such a short photoperiod? i know the corals will do fine under the lights for 5-6 hours, but with 8 hours you will get so much more growth, plus closer to reality. unless you are dealing with an overcrowded tank, in which case frag your corals and send me some.

[siskiou]

Lighting period is short because the corals in that tank have been under PC lighting until recently, so I don't want to fry the poor things!

Nothing much in there yet that needs the longer lighting period and there are VHOs for the rest of the time.

 

Overcrowded tank?! I wish!!

[downhill_biker]

ok. sounds good. i am actually in the middle of the same thing. i had the photoperiod too high after getting the new metal halides and ended up light shocking my tank. here is what my corals did when the new lights hit them, and where they are now.

 

When I got the frags new:

 

Here's the light shock. RTN and Bleaching:

 

Here's the corals now:

 

So you are right. Light shock can cause major havoc, and i still only run my Halides for 7 hours a day, and everything is doing fine. I will probably up it to 8 hours soon. Hey you are in Eugene, you should come over and check out my tank, and meet me.

[Nyles]

I have a frag of that blue tip local as well if anyones interested... .