MH bulbs

howdy20012002 · #1 07-20-2006, 01:29 AM

I have a question...
For MH bulbs, do u wait to change them once they burn out?
Or do they lose their wattage as they get older like PC?
If yes, how often should u change them...my 90 came with the used MH bulbs and I am not sure how old they are.
As well, is there really that much of a difference in the different brands of bulbs?
Thanks for the info
Neal

fortheloveofcrabs · #2 07-20-2006, 02:01 AM

Hey,

MH bulbs can burn for many, many, many, many years... Well, maby not that long, but for a good while any-hoo. You should change them "every 12 - 18 months" because their spectrum starts to shift down. IE they become more yellow. As far as brand goes, yes there does seem to be a difference in my experience. I've used Hamilton, Sun Aquatics, XM and Radium. From what I've seen, you pay for what you get. The Radiums held their color for longer, and burnt brighter. Sun Aquatics bulbs are great - for a sump. Hamilton and XM seem to be a good middle of the road bulb - XM (I feel anyway) is the better of the two brands though. Keep in mind though, you need a pulse ballast to run Radiums.

Hope this helps!

*This is all just my opinion - so please don't pick on me!

Quinster · #3 07-20-2006, 11:44 AM

Quote:

Originally Posted by fortheloveofcrabs

Sun Aquatics bulbs are great - for a sump

Tell that to the SPS Clams Anemones LPS and all the other contents in my 2 tanks...LOL

OCDP · #4 07-20-2006, 02:36 PM

Different results for different people sometimes..

What are we talking about here? Mogul based? Or Double Ended (HQI) Metal Halide bulbs?

Delphinus · #5 07-20-2006, 04:20 PM

The rule of thumb for changing them out at regular intervals doesn't really matter if it's SE or DE. In general though I've found that the higher the kelvin the sooner the shift.

As for the question of whether brand matters... I'm afraid that's really a question you need to answer for yourself with some experimentation over time. In general though, you get what you pay for. Having said that, there are a number of new bulbs on the market these days that are "economical" in comparisons to others and they seem to be just fine.

The one thing that I recommend though is trying to match bulbs to ballasts. This can help narrow down the choices when trying to decide what to try next. I.e., a manufacturer may put in their specs that a lamp should be run on a pulse-start or a probe-start ballast. Not that vice-versa can't work but sometimes you get sub-optimal results. I.e., if you try to fire an Ushio on a probe start ballast it may take up to 30 minutes after powering on for that lamp to actually light and stay lit. (After a while it gets better.. I ran Ushio's on probe starts for many years but if I could go back and do it again I'd have bought pulse-start ballasts... I bought the ballasts before understanding any of this kind of stuff.) Now that Iwasaki has a 175W 14000K lamp I'll probably never use an Ushio on my one remaining probe start 175W ballast -- I sold off the others. Great lamp, awesome colour, super bright, and intended to be run on M57 (probe start) ballasts. Unfortunately a bit pricey but with the 6500K Iwasaki's tending to be good for up to 24 months I'm hoping some of that Iwasaki quality spills over into this new line as well.

BTW Iwasaki's (6500k's) tend to have the best bang for the buck as far as PAR (photosynthetically active radiation) is concerned. If you want wicked coral growth these lamps are hard to beat. But a lot of people find them aesthetically unpleasingly yellow requiring a lot of actinic to balance out and make white. I generally wasn't unhappy with the colours after using them for a while (in fact that was the only period I really had nice SPS was when I used those lamps, but I shouldn't really mention that as there were other factors involved..) I switched to 10k's last year as I wanted to try a bluer look to see how I would like it. Also generally speaking the bluer the bulb the more colour you get out of corals.

Also one last thought, electronic ballasts (a third option over probe-start and pulse-start). Generally speaking if you have electronic ballasts then you don't need to concern yourself about lamp selection since they will usually fire any kind of lamp (of the correct wattage). Only thing is, they tend to underdrive the lamps slightly. Some people claim to notice the lights are less bright (I can't say for myself, I've never tried electronic ballasts .. I did try one, but I broke it before I ever got to use it.. $150 paperweight.. more on this later). But it does result in longer lamp life, which is a good thing. It also probably means your power bill is few cents less than it would be otherwise. And they say there's less heat from the ballast. The only drawbacks I see to electronic ballasts are 1) the cost, they're more expensive and 2) depending on the brand, if you break them (i.e., there's a short in the wiring somewhere), they're dead. Icecap ballasts can supposedly be sent in to the factory and get repaired, but other companies don't do such things. The one electronic ballast I tried was a circuit board encased in epoxy. There's no way to fix such a beast, so I had to trash can it. What happened was I was trying to DIY a DE fixture, and accidentally contacted one of my lamp leads to ground (I thought I was being cautious by grounding the fixture.. I read afterwards the warning "Do not contact lamp leads to ground". So much for that.)

Anyhow hope some of this info helps.

PS/Edit. One last thought (I realize I said "one last thought" already so this is "and yet another one last thought"), there are also "HQI" ballasts but that's a whole other discussion (they are still considered pulse-starts generally). 150W and 250W HQI ballasts exist which tend to overdrive the lamps slightly, giving a brighter look overall. Despite what you may read, there's no such thing as a 400W HQI. PFO markets a ballast labelled as such, but it is a really a 430W SonAgro ballast (actually intended for Sodium lamps, not Metal Halide -- but will run pulse-start MH lamps just fine -- just overdriven slightly).

howdy20012002 · #6 07-20-2006, 04:49 PM

I personally have coralvue electronic 400 W ballasts
thanks everyone for the info...greatly appreciated.
I am going to try a couple of bulbs off Ebay and see how they work.
thanks again,
Neal

Samw · #7 02-04-2008, 01:51 AM

Here's some info for this old thread. I came across this article as I was Googling for Phoenix bulbs. It claims that the MH bulb that is being tested lost around 20% of its output by month 6. By month 12, it has lost 25%. By month 18, it has lost 30% of its output. By month 24, it has lost 34%. By month 27, it has lost 37%.

Light Output of the Phoenix 14,000K DE MH Bulb Over Time

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

"The light output of the six Phoenix bulbs shows an initial decline over the first three to four months and then levels off at about 75% of their initial output. From these data I raise the question: “If a bulb is not replaced at six months, when it has lost 20% of its output, then why would we replace it at 12 months when its output has fallen only another 6%?” It may be more cost effective to plan the lamp number and placement based on 70-75% of the bulbs' initial output levels. "

"this bulb would appear to still maintain 70% of its output at 18 months, 66% at 24 months and 63% at 27 months of use. "

Quote:

Originally Posted by howdy20012002

I have a question...
For MH bulbs, do u wait to change them once they burn out?
Or do they lose their wattage as they get older like PC?
If yes, how often should u change them...my 90 came with the used MH bulbs and I am not sure how old they are.
As well, is there really that much of a difference in the different brands of bulbs?
Thanks for the info
Neal

midgetwaiter · #8 02-04-2008, 04:36 AM

Quote:

Originally Posted by Samw

Light Output of the Phoenix 14,000K DE MH Bulb Over Time

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

"The light output of the six Phoenix bulbs shows an initial decline over the first three to four months and then levels off at about 75% of their initial output. From these data I raise the question: “If a bulb is not replaced at six months, when it has lost 20% of its output, then why would we replace it at 12 months when its output has fallen only another 6%?” It may be more cost effective to plan the lamp number and placement based on 70-75% of the bulbs' initial output levels. "

"this bulb would appear to still maintain 70% of its output at 18 months, 66% at 24 months and 63% at 27 months of use. "

I hate this article sooooo much. It's a nice bit of work but people are completely ignoring why the author managed to get the numbers he did and IMO are going to big in for a big surprise when they try and duplicate the results.

He's using Ice Cap ballasts, this makes for a substantial difference in the bulb's useful life. You may be able to get close to this kind of life with other electronic ballasts but you sure aren't going to get anywhere near it with an HQI. 6 to 9 months with a Pheonix or Aquaconnect on an HQI and it's hosed.

They really need to make this point in the article.

StirCrazy · #9 02-05-2008, 03:10 AM

Quote:

Originally Posted by midgetwaiter

with an HQI. 6 to 9 months with a Pheonix or Aquaconnect on an HQI and it's hosed.

What are you basing this off of?

Steve

X-Treme · #10 02-05-2008, 04:11 AM

So.......I'm running a Giessmann 250W DE fixture with an Icecap ballast and 13K Giessmann bulb and would like it a BIT bluer. I am coming up on the one year mark for the bulbs and am wondering if going to the Giessmann 14.5K is gonna be any noticeable difference or should I go to thier 20K or a different brand completely. I am just kinda scared that the 20K might be TOO blue. There are also 4 actinic T5s in the fixture.