M58 vs M80 balllast, help please.

[KH971]

I am going to up grade to a larger tank, and i will need 4 250 ballasts, I am not fully sure what bulbs i will run, XM probably, but I do like to experiment.
The M58 is not a pulse start correct?
What are the differences between the M58 and M80? What are the pros and cons of each? Will the M80 run more bulbs than the M58?

Thanks Keith

[prodman]

The m80 ballast will give you more light output and use more watts. You should checkout this thread thats at the top of this fourm http://archive.reefcentral.com/forum...hreadid=624185

[thrlride]

The m58 will run the XM as designed, the M80 will overdrive it giving you a little more light but also shortening the life of the bulb.

[KH971]

Does the M80 give me the option to use more different bulbs?
Also does it use more power?

[thrlride]

If you want a great ballast to not limit your choices on bulbs you'd have to go electronic.

The m80 will use more electricity as well.

[moonpod]

The M80 is really designed for Double Ended/"HQI" 250w bulbs. These are very effecient ballasts, but do run around 300w in reality--which is appropriate for DE bulbs, but not SE. It will run Single Ended/Mogul style bulbs, but as previously stated overdrives 'em and will give the bulbs shorter more glorious lives.

The M58 is a probe start and will run the vast majority of SE MH bulbs out there appropriately, but you can have trouble with pulse start bulbs. There are "tricks" to condition the bulb to start and run on the probe start ballast, but there can be problems. The pulse start ballast is like the M114 or something like that. I can't remember the exact ANSI code. Conversely I believe that pulse starts can cause problems with probe bulbs.

Electronics are great for flexability in terms of they will run all bulbs. They are also more effecient (as a generality) in a watts expended vs PAR output than the probe or pulse start ballasts. M80s have the same effeciency as the electronics, but again are really only for DE bulbs--conversely electronics underdrive DE bulbs. The lower wattage run through the bulbs should also in theory preserve bulb life, but the electronic start up method is thought by some to be not so good for the bulbs and it's not like there's really well documented experiments demonstrating the bulb life differences among the various ballasts.

[KH971]

Thanks Moonpod, that answers my question. i will probably go with the M58's since I am planning on quad VHO/s so i can add some seroius actinics to the tank. I do like the look of actinics, but duals just aren't enough for me. Plus having quad VHO's on diffrent timers to really simulate sunrise and sunset.

[Siffy]

Hope no one minds me jumping in here to ask this. But... If there aren't any well documented experiments or even any seemingly valid opinions (with numbers or references to personal examples) how can people keep saying "this/that will shorten bulb life"? I'd mainly like to know how much shorter? Also, does that apply to how long the bulb will burn (bulb life according to most of the world)? Or does it apply to how long the bulb will emit the desired color spectrum (bulb life according to some but not all reefers)? Since the latter isn't even documented well to establish a base case, it's even speculation.

[moonpod]

There are PLENTY of empiric stories of SE MH bulbs color shifting and fading prematurely on "HQI" ballasts. That being said, the lower K bulbs tend to "tolerate" it better than the higher K as a generality--ie the classic example was radiums with significant color shift and fade after 6-9 mos whereas Ushios have been here and there tested with no significant color shift and 80+% of baseline output at 12 mos. Some of it also depends on how often you are gonna change your bulbs anyways. The "natural" history of the bulb is to slowly color shift and lose output until it reaches the end of life where it won't start at all. That however tends to be much past the point where most reefers will change the bulb out.