Difference betwen HQI and HID

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jmhart

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So I'm in the beginning stages of putting together my 180g tank(by putting together, I mean, in Excel as a proposed budget/purchase list, not physically). I'm leaning towards a 3x~150w MH and 4x80w T5 retrokit available on Catalina Aquarium.


My question: What's the difference between HID and HQI? From my searches, it seems that all HQI are HID, but when something is listed as HID and another is HQI, what's the difference? It seems that HQI is single ended, smaller, and more intense. Is this the basic difference.

I'm looking at two fixtures:

3x150w HQI/4x80w T5 for $950
3x175w HID/4x80w T5 for $600.


My plan is for the T5 to be my primary lighting for 8 hours a day, but run the MH for ~3 hours a day as a burst/for my viewing pleasure.

For my needs, is there any reason to get the HQI? It would sell so much easier to my wife if I can use the HID's. I'm in the range of $2200 for the upgrade from a 45g to a 180g tank, so cutting my cost I can is a big plus.
 

Sploke

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I thought HQI was double ended?
 

Sploke

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Ok, here is my take on how I understand the fancy lighting market. This is all based on my research into MH lighting for a reef setup, mostly from RC.

HID lighting is a general category that encompasses metal halide, high pressure sodium, T5HO, and mercury vapor. Any high-intensity fluorescent technology, as far as I can tell.

HQI are smaller, double ended bulbs and usually (or always?) run on electronic ballasts.

Regular single-ended MH bulbs (sometimes referred to as "mogul-base" - larger than a regular incandescent base) come in a few different flavors. There are pulse-start, probe-start and regular ones. The pulse-start and probe-start need the appropriate ballast (magnetic or electronic) to provide the arc to initiate the bulb to start burning, and as far as I can tell, they are not cross-compatible. There are also single ended MH bulbs that behave like HQI, with an electronic ballast providing the arc to get the bulb going rather than a mechanism inside the bulb itself (as a pulse-start or probe-start bulb has.)
 

Spewn

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Mar 12, 2008
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My understanding is that arc-tubes in HID bulbs produce visible light, fluoro bulbs don't. In addition to high pressure and heat, that is. I wouldn't consider T5's High-Intensity Discharge.

Really, they're smaller, so they pack a lot of light into a tight area. And it's not just the bulb size, but the size of the arc tube. Even Power-Compact fluoros have a massive surface area compared to the tiny space an MH arc-tube takes up. For a lot of aquarium applications I can see this not being important. For very dense foliage, HID lamps are the best(only?) way to get light to the lower leaves and plants.

Edit:

Ooops ;)

HQI is a type of HID lighting. http://en.wikipedia.org/wiki/Hydrargyrum_quartz_iodide I guess, a sub-type of MH?

I don't think that HQI has anything to do with the bulb being double-ended. I know HID doesn't.
 

jones57742

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Mar 18, 2006
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My plan is for the T5 to be my primary lighting for 8 hours a day, but run the MH for ~3 hours a day as a burst/for my viewing pleasure.
Jeff:

You are way senior when it comes to plants and although I was way out of pocket when you posted your first thread I just flat could not post in order to provide input which was disappointing as you have helped me a bunch.

Still not running good but I am glad that, I believe, the tank which you decided on is a 6'x2'x2' which was where that I was headed if I could have posted. The 2' deep and 2' wide is first class wrt maintenance and the 6' fits the standard lighting dimensions.

You are "right on track" with the MH for 3 to 4 hours per day not only for viewing but also for your plants.

IMHO trash can the T5 concept and go with PC (I actually did this with several $K worth of T5 when it was not a concept).

IMHO also trash can the HID concept as this form factor is off breed from the mainstream and will probably go away with time.

On my 36" tank I have two PC's and one MH.

When I trash canned the T5's I replaced them with my first PC fixture.

This was in my very early fish keeping days and obviously when I powered up this fixture on my tank I ordered another identical fixture.

For several months I experimented with varying fert concentrations and lamps (the final one in that configuration was three 10000K bulbs and one 7100K bulb).

Still not being happy with my plant health and growth I ordered a HQI-MH fixture.

After a year of experimenting this is what I have:
One 6700K PC bulb in the back;
One 10000K PC bulb next;
Two 10000K MH bulbs next;
One 10000K PC bulb next; and
One 7100K PC bulb in the front.

I am still experimenting with fert concentrations and lighting durations.

The lighting permutations and combinations include but are not limited to what you proposed in addition to varying the MH period, alternating PC on/off and MH days on/off, etc.

TR

BTW: When you get into your wet/dry filtration thread I hope that I can provide some decent input.

http://www.marinedepot.com/ps_ViewItem~idProduct~CU01063.html
 

Sploke

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What is your reasoning behind using PC over T5HO? Given the choice I'd rather the T5HO - the PCs lose some efficiency with restrike due to the design of two narrow tubes side by side.
 

jmhart

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Jones,

Regarding HID vs HQI, I was curious about that. I wasn't sure if one of them was destined to go the way of the Dodo. It woudl be a shame to buy a fixture and then not be able to acquire bulbs for it with in a few years.

Why do you recommend PC over T5? I currently use T5, but a majority of the members of the local plant club suggest T5 over PC....I can't say I've heard a good argument for either one.

Where do you purchase your 7100k PC bulbs? I currently use 36" 96w PC bulbs, but have only been able to find 6700k and 10,000 bulbs. One of the draws of the T5 is greater bulb variety.

Finally, I've haven't fully decided on filtration. I'm leaning towards 2 Eheim 2128's with some plumbing for inline instrumentation. I may include a sump, but only if I seal up the "dry" section to prevent co2 loss.
 

Mgamer20o0

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Jun 4, 2003
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t5 ho are better then pc. they run cooler and get more light into the tank more so when you have individual reflectors. the price have been coming down too. more and more people will be switching to them. personally i would just go with a full t5 ho set up. mh might look good but i dont want to deal with the heat. on the subject of hqu and hid i have no clue.
 
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