HQI vs. Mogul

[jmaneyapanda]

In the spirit of our recent ARC meeting, I have a question regarding HQI vs. Moguls. I am looking into a 400 watt setup, and am debating between HQI and Moguls. I have always run mogul bulbs on a blueline electronic ballast and have had no complaints. However, that choice was due to the fact I had no idea what HQI was at the time. Now, I do, and the options are driving me mad. Here's some points that perhaps someone can correct me or clarify for me:

1) HQI need to run on an electronic or HQI ballast, while moguls have many other options (although most are bad options).

2) When all is said and done, the HQI should produce more PAR than Moguls.

3) I would like to stay with an electronic ballast due to heat issues and bulb reliability, but how different are the brands between the electronic manufacturers?

4) Do generic electronic ballasts (not Ice Cap or Blueline) merit any consideration, or is that like buying a magnetic ballast?

Any help or thoughts would be appreciated. Thanks.

[MattTVI]

1) No, there are magnetic ballasts that will run HQI bulbs, I think ANSI M81 runs the 150s

2) Not sure, they produce a lot more PAR w/out a shield (mogul bulbs have a UV shield in the bulb), but it seems to me the PAR levels could be effected by the type of UV shield you pick (clarity, thickness, etc.)

3) Not sure, IceCap has a good reputation... can't go wrong there...

4) Again, not sure, I've heard a viscious rumor about icecap slapping their blue casing around the same ballasts as... well, "generic" companies, but that's unsubstantiated... :-)

[jmaneyapanda]

HQI should NEVER be run without the UV shield, correct?

[Kullas]

correct, i guess it could be run without but it could mess with your eyes.

[GeorgeW]

Originally Posted by jmaneyapanda

HQI should NEVER be run without the UV shield, correct?

To my knowledge, correct.

[GLXTRIX]

it not only will mess with your eyes but it'll harm your corals and fish. Always, always, always have a UV shield covering the bulb.

[jmaneyapanda]

ANy most fixtures come with this UV shield already, so its not a matter of picking a selecting, it's just what comes with the fixture, right?

[is_that_a_fish]

i believe the main difference between the two bulbs is that a hqi blulb will light up more of an area if that makes any sense, and the hqi doesnt have the uvi blocker built in. correct me if im wrong.

[mufret]

The reflectors used will really have a larger impact on the spread of the light vs the type of bulb used. As for bulbs, there are now some new SE bulb (Iwasaki) that meet or exceed the PAR of many DE bulbs. The "color" of the bulb will also make a difference. I use both and normally my setup (canopy, amount of room over the tank, etc) determines which type of bulb I use.

[MattTVI]

I should clarify, the reason I mentioned high PAR levels w/out UV shielding on HQI bulbs is that some sites present PAR data on unshielded bulbs along side the PAR values of SE bulbs, making them appear to be much more powerful than SE bulbs which have a built in UV protection. As far as I know, if you ran HQI's w/out any type of uv protection you would end up harming your live stock.

[Schwaggs]

First, you really need to check out http://www.reeflightinginfo.arvixe.com/

1) Both DE and SE have the same amount of ballast choices (technically, SE have more types if you consider probe start and pulse start types of magnetics). Typically, modern electronic ballasts will drive either type of bulb. If you go magnetic, you will need to match the type of ballast to the type of bulb you wish to use (SE Probe start, SE Pulse start or DE).

2) It depends. If you compare a SE bulb without an additional shield to a DE bulb with the required shield, the SE bulb can yield more par (using the same electronic ballast). HOWEVER, when you use a SE bulb without an additional shield, you should mount it fairly far from the water surface (8 to 10") to prevent water splashing on the SE bulb and breaking the outer glass. With DE bulbs, inside a fixture with a separate UV shield, you can mount the bulb much closer to the water surface, which can yield significantly higher par as long as you keep the glass clean.

3) I'm not sure but the above link should be able to help with this. I use Icecap electonic and Blueline magnetic HQI ballasts with great results. IME, the magnetic ballasts don't even get warm to the touch so it shouldn't be an issue with Blueline magnetics...

4) Not sure.

You should also consider the "overdriving" effect of the M80 HQI Magnetic ballast (used in most 250W HQI magnetic ballasts I belive). You can get nearly the same PAR as a 400W fixture using a 250 W DE bulb and the M80 DE magnetic ballast.

You MUST use a UV shield with DE bulbs or you will kill your corals. The UV will burn your corals similar to sunburn.

[mojo]

Yup- what Schwaggs said.

Also, note that while HQI typically does give more PAR at the same height as a equivelent-wattage SE bulb, but they have a more focused "beam", so that you'd need more of them for the same surface area. What you make up in increased PAR, you'll lose in coverage. This ususally doesn't affect things enough to warrant more lights, but be aware of it. You will get better depth penetration with an HQI setup.

[jenajet]

This answered my question too.

[PowerManJ316]

Schwaggs is exactly on...check out Sanjay's website. It is very helpful. Keep in mind that typcially magnetic ballasts (and HQI) overdrive the bulbs as Schwaggs mentioned. This means that a 250W HQI ballast (M80) is typically driving the bulbs at about 350+ W. This explains why the HQI ballast is putting out so much more par. Does this mean the HQI is better??? NO! The HQI is consuming more energy and thus it SHOULD be putting out higher PAR. You first have to decided how much PAR you need and then choose wisely. Do not be fooled by the HQI simply because it puts out more PAR - there is a catch that is higher energy consumption. Personally, I always check the efficiency as well.

One final note...To my knowledge there has not been a study showing the long term effects of overdriving bulbs (running 250W bulbs at 350+W). I have an electrical background an would guess that overdriving a bulb will shorten the effective life of the bulb considerably. As the wattage increases, the voltage is effectively staying similar which means the current through the bulb is drastically increasing. IMHO, this has to cause increased wear and tear on the bulb.
HTH, let me know if you still have any ????'s
Jeff

[mojo]

Originally Posted by PowerManJ316

Keep in mind that typcially magnetic ballasts (and HQI) overdrive the bulbs as Schwaggs mentioned. This means that a 250W HQI ballast (M80) is typically driving the bulbs at about 350+ W. This explains why the HQI ballast is putting out so much more par. Does this mean the HQI is better??? NO! The HQI is consuming more energy and thus it SHOULD be putting out higher PAR.

Actually, I have to disagree, based on my own testing done with 250w Phoenix 14k and Hamilton 14k DE bulbs with IceCap and M80 ballasts on a PFO HQI mini-pendant. Tests were done 9" from the bulb + 5" under water. Power draw was measured using a Killawatt meter and PAR was measured using an Apogee handheld meter:

Icecap / Phoenix: 250w power draw. 225 PAR
Icecap / Hamilton: 250w power draw. 250 PAR
M80 / Phoenix: 310w power draw. 275 PAR
M80 / Hamilton: 310w power draw. 300 PAR

In short, the Hamilton 14k bulb always produced more PAR. The M80 ballast allows both bulbs to draw around 310w. The important part: the Icecap ballast seems to limit the power draw to 250w, no matter what the bulb. I've since tested that with a XM 10k mogul bulb, and also get 250w power draw through the electronic ballast.

In short, the electronic ballast will limit your draw and will not overdrive either bulb. The magnetic ballast will allow both HQI and SE bulbs to pull abou the same (not surprising since a HQI bulb is the same as a SE bulb, but without the outer envelope).

The higher PAR that results from an HQI setup is due to the fact that the reflector can be much closer to the bulb itself, resulting in a more focused light, and thus more PAR directly below the light. Again, a tradeoff of intensity vs. spread.