MH...Double Ended vs. Mogal Base....

[segraves1]

ok....so I'm ready to step up to MH......I am going to build my own top.......

looking around it seems Double Ended MH (bulb and ballast) costs about twice as much as Mogal Base MH.....the question I have is

WHY

if you have:

a 250Watt Double Ended MH (with a PFO 250W HQI ballast made for double endeds)

AND

a 250Watt Mogal Base MH (with a M58 ballast)


I would take it that the Double Ended SHOULD be brighter right (I mean.....it costs twice as much......)?

but does it really do twice as much light? how much brighter is it really? is the light "better" in some way?

[segraves1]

other question....whats the difference between:

- 250W Advance Magnetic M58 / H37 Ballast -Metal Halide

- 250W -HQI, Advance Magnetic M80 Metal Halide Ballast


there are also some other ballasts here:

http://www.hellolights.com/elbalmethal1.html

why one vs. another.....whats the cheapest/best combo?

[dakar]

You'd think for the price the DE would be as my daughter says "all that", they are nice in the way they take up a smaller amount of space, and with the right bulb, reflector, and ballast they produce a tremendous amount of PAR. Worth the price? That depends on the buyer. Personally I think the prices are horrifically inflated due to nothing more than the current popularity.

But if you do your homework you will find there are complete SE DIY setups that are far superior (my opinion) or equal to the PAR that can be had for less than the price of just a DE bulb.

Study the spectral charts, PAR, and efficiency of the bulbs/ballasts you are considering and make an educated choice. Keep in mind the quality of a reflector will make or break even the best bulb, single or double ended.

[segraves1]

any suggestion on what kind of reflector setup I should look into?

[dakar]

M58 - 250w Metal Halide (probe start)
H37 - 250w Mercury Vapor (probe start) (awesome for Iwasaki bulbs)
M80 - 250w HQI (DE)

The HQI ballasts have an ignitor similar to pulse start SE ballasts... (just how similar I'm going to find out one of these days with yet another mad scientist type experiment)

[segraves1]

nm...lol...missed that (DE) part.....


so does that mean the M80 could work for either DEs or Mogal base bulbs (ie: one ballast can do anything)?

[segraves1]

ok....I'm not understanding what the difference between HQI and "regular" MH bulbs is.....

[dakar]

Here's a cross reference chart of the ANSI codes for ballasts and their respective bulbs that should help.

http://www.captivereefing.com/viewtopic.php?t=394

Even for mogul bulbs/ballasts you need to look for the 'start' type, probe vs. pulse start. I'd reccomend staying away from the pulse starts, the variety of bulbs available is limited, and they get expensive fast.

As far as using an M80 (DE/HQI) ballast to fire Mogul (SE) type bulbs it is not reccommended (actually the manufacturers say some really bad things can happen...like fire), can it be done... yes, with some bulbs they will work, but you will sacrifice the usable life of the bulb (if it doesn't kill the bulb or ballast completely). You are better off to stick with the proper combinations.

For Mogul reflectors, the batwing type such as those sold by hellolights are some of the better ones out there (I use them if that means anything).

[segraves1]

so how does this look:

250W Advance Magnetic M58 / H37 Ballast -Metal Halide
250W 6,500K Iwasaki
MH Parabolic Reflector Set w/ Mogul Base


any reason this wouldn't work?

[dakar]

IMO that is the perfect setup for a 250w halide....

[segraves1]

cool, thanks man.......


do 6,500K Iwasakis really output at 6500K? why do people like the 6500K so much?

reading over some stuff about the 6,500K Iwasakis, it seems like people have to suppliment them with 03 Blues......

if true, then that could really quickly get be right back up to the cost of a double ended.......


(I know it seems like I'm going around and around and around here....just don't want to dump money and then go "wow....wish I had asked that question first....").... :)

[segraves1]

also came across a post that said people who are using the 6,500K Iwasakis love how they make corals grow like crazy but everyone says it takes LOADS of 03 Blue to balance out the yellowish light......true?

so as I take it, corals actually like the 6500K light better than the 10K or higher light?

[dakar]

The blue's are more for our eyes. The Iwasaki's produce light that appears slightly yellow, supplementing with actinics balances out the yellow hue and makes it appear a very brilliant white, while making the fluorescent colors glow. Most people running 10K bulbs run actinics as well. Personally I prefer the actinics that peak at 450-460nm (really blue) compared to the 03's that peak at 420 (purple).

The actinics make for nice dawn/dusk effect for your tank as well, a good transition for your critters before the intense halides come online.

Why people rave over the growth from the 'saki's is because they are amongst the only true 'full spectrum' lamps on the market. Full spectrum in that they produce intnese lighting across all of the visable spectrum, hence the yellow hue. But like I tell anyone else about lighting, go outside andlook up at the sun...what color do you see? Not white and definately not blue. Photosynthesis has been proven to occur at the red end of the spectrum all the way up and beyond the violet into the UV range. Why starve your animals of the full lighting they would otherwise have in nature?

Lot's of folks to argue what bulb is the best for this and that... but at best it can be l can be left to scientific proof or at worse personal choice.

Here's a thread that might be helpful, loaded with charts and spectral plots about the subject.
http://www.captivereefing.com/viewtopic.php?t=1188