Your Metal Halide Questions Answered

[filefish949]

^^^ Sup Flatlander.

I actually had a pretty knowledgable LFS owner tell me a couple of months ago...MH bulbs dont need replacement until they burn out????

He said hes checked par rating as the bulb ages...yes the par output decreases...but not enough to be a factor to change the bulb.

I have nothing to back this... Just FYI

 

Izzue

 

 

that is true, sort of, the reason they lose par value is the electrodes inside the lamp splatter a bit on start-up in the start-up. small amounts of the electrode coat the inside of the envelope and sort of tint the glass. this is one of the main advantages of a good e-ballast, they fire in as few as 2-3 cycles, as apposed to magnetic which take around 40 cycles to fire

 

halides do create more UV which encourages the corals to produce more pigments which are the colors we like to see

 

 

the one point, and it is actually 2 fold, that I would take issue with is a matter of efficiency, which translates to heat and electric bill.

 

in short, halides will give you more light for less money. that is to say they are more efficient. they produce less total BTU per lumen and require less watts per lumen. what this means is that if you ant to achieve the SAME PAR VALUE with T-5, the T-5 setup will require more watts and produce more heat than a metal halide setup producing the SAME par value. this is not true with 20k halide lamps

 

 

I probably missed it but what K is best for SPS coral growth? I currently running 150Watt 14,000K Phoenix bulb. I have a bunch of SPS now and growth is pretty SLOW.

 

 

6500 +VHO actenics

Edited December 7, 2007 by filefish949

[Reef Chicks]

Hello folks... n00b here with a question...

 

Some recently history: I have a BC29 with a stock hood. I am looking to get MH and did some research on here and found lots of people who mod a $10 300w hallogen lamp from Walmart into their hoods. So, I have two 70w MH ballasts from ballastwise on the way. Now I am looking for cheap bulbs on e-bay - if this idea doesn't work out I don't want to have spent tons of $$$ - but all the 70w bulbs I find are HQI. Is there a difference in ballast and/or lamp that would run those? In other words, can I run an HQI bulb on a regular MH lamp and MH ballast or does it need its own HQI lamp & ballast?

 

Thanks for the help guys!

[ReeFur]

HQI is METAL HALIDE

[Izzue]

Hello folks... n00b here with a question...

 

Some recently history: I have a BC29 with a stock hood. I am looking to get MH and did some research on here and found lots of people who mod a $10 300w hallogen lamp from Walmart into their hoods. So, I have two 70w MH ballasts from ballastwise on the way. Now I am looking for cheap bulbs on e-bay - if this idea doesn't work out I don't want to have spent tons of $$$ - but all the 70w bulbs I find are HQI. Is there a difference in ballast and/or lamp that would run those? In other words, can I run an HQI bulb on a regular MH lamp and MH ballast or does it need its own HQI lamp & ballast?

 

Thanks for the help guys!

 

Not totally sure what you are asking...but heres a stab.

Metal halides come in 2 type of bulbs. (for aquarium purposes)

1.HQI...is a double ended smaller bulb (latchs by spring ends)...known to put off less heat then MG

2.MG...or mogul ended bulb...single end that screws in. Little hotter bulb.

 

Both bulbs come in different wattages and Kelvins.

Your ballast should support the exact wattage bulb...this usually makes it HQI or MG.

Then you just need the appropriate retro hood and connectors.

Hope this helps.

 

Izzue

[Reef Chicks]

Thanks guys! Yes, your answers help a lot... an HQI is just another name for MH and does not require a different type of ballast and/or lamp.

[shaggydoo541]

in short, halides will give you more light for less money. that is to say they are more efficient. they produce less total BTU per lumen and require less watts per lumen. what this means is that if you ant to achieve the SAME PAR VALUE with T-5, the T-5 setup will require more watts and produce more heat than a metal halide setup producing the SAME par value. this is not true with 20k halide lamps

 

This is a very broad statement. This thread is about MH and MH is a great lighting source but how can you say T5 will require more watts, more heat and produce less par in all situations? What t5 lighting setup are you referring to? What bulb types?

 

T5 has so many options that a blanket statement like this is entirely false. I currently have 432w of T5 over my 120g. There is a crocea in my sandbed and I have been able to grow colorful zoas and sps in all depths of my tank. Can you light a 120g with under 500w of mh and see the results I have... not possible, as you would need at least 2 250w hqi bulbs and some actinic supplements to achieve the desired coloration. My tank increases 0 degrees when the lights are on (no mh system can say that), the heat may be there but with t5 you can easily blow the heat away so there is little to no transfer to the tank.

 

When it comes to par, if you had 432w (8 bulbs) of 6.5k ge T5 bulbs over a 120g tank you would have so much par that you literally could keep 0 corals because they would all bleach and die; the tank would be a tad yellow though I also paid $440 for my 4 retro kits... definitely cheaper than any MH options I could find.

 

Bottom line, MH is a great choice in many circumstances but lets try to avoid blanket statements like the quoted one above as it is obviously not true.

[ReeFur]

do SE bulbs need a glass shield like DE bulbs?

[shaggydoo541]

No they do not.

[ma_sha1]

I have done DIY conversion on Hardware store MH flood light, appears no difference except the bulb kelvin.

 

I used a single end medium socket (normal household socket) bulb 70W MH fixture, swap put the bulb into a 70W 6500K Iwasaki medium base Aquarium MH bulb (Can be hard to find). It runs perfect for the past 5 years. But for the 70W, unless it's is HQI (Which you can convert as well from Halogen fixture as covered by other's threads) you can not get higher kelvin than 6500K bulbs.

 

Recently, my newest MH DIY is from 10,000K Automotive HID MH light,

for details check out my 4G Pico W 35W Metal halide thread.

http://www.nano-reef.com/forums/index.php?...p;#entry1415752

 

I'm thinking of adding a MH fixture to my 20gal long tank. Currently I'm running a 30" CF light, but I'd like to add clams and SPS to the tank.

 

I'm wondering what the difference is between a MH fixture you buy from a fish store and one bought from a hardware store. I do know that the hardware store fixtures are MUCH MUCH cheaper.

 

If anyone has had personal experience with building their own fixture using a MH bought from a hardware store, please let me know what your experience has been.

Edited December 26, 2007 by ma_sha1

[filefish949]

This is a very broad statement. This thread is about MH and MH is a great lighting source but how can you say T5 will require more watts, more heat and produce less par in all situations? What t5 lighting setup are you referring to? What bulb types?

it is simple math and physics

 

 

T5 has so many options that a blanket statement like this is entirely false. I currently have 432w of T5 over my 120g. There is a crocea in my sandbed and I have been able to grow colorful zoas and sps in all depths of my tank. Can you light a 120g with under 500w of mh and see the results I have... not possible,

 

sure 3 x 150, depending on kelvin you would have 20-100% more par

 

as you would need at least 2 250w hqi bulbs and some actinic supplements to achieve the desired coloration. My tank increases 0 degrees when the lights are on (no mh system can say that),

 

well here is a blanket statement that is not true, let's try to avoid those

 

the heat may be there but with t5 you can easily blow the heat away so there is little to no transfer to the tank.

 

When it comes to par, if you had 432w (8 bulbs) of 6.5k ge T5 bulbs over a 120g tank you would have so much par that you literally could keep 0 corals because they would all bleach and die; the tank would be a tad yellow though I also paid $440 for my 4 retro kits... definitely cheaper than any MH options I could find.

 

Bottom line, MH is a great choice in many circumstances but lets try to avoid blanket statements like the quoted one above as it is obviously not true.

[shaggydoo541]

it is simple math and physics

 

Lets add this up, 3 x 150 = 450.... my t5 system has 432w, since 432 is less than 450 I guess math is on my side. Now with physics you have to get fairly complicated and figure out how much energy is lost to heat, lost in the wiring, lost in the ballast, lost to any other non-usable energy source, etc. and all this energy loss would have to be compared to what energy is usable by our corals (which is a huge debate in and of itself).... so lets just not go there. So physics smysics is about as honest of a debate as you can have as to which lighting source is better. There are so many variables that NO one has honestly considered them all.

 

So I believe you need to retake both math and physics

 

sure 3 x 150, depending on kelvin you would have 20-100% more par

 

If you could get 20-100% more par (which is a huge range and I suspect you just made that up on the fly ) with MH, than why is T5 so popular? Because people are bored and T5 sounds like such a cool name... yeah thats probably why

 

So lets think of the best 450w MH system for par... what would it be iwasakis??? or maybe something else, it really doesn't matter. But lets consider my option of 8x54w 6.5k ge... again with this setup you could not keep a single photosynthetic coral in a 120g tank... the corals would simply fry. Under the MH system I know you could keep a wide variety of corals no matter what the kelvin rating of the bulbs because the 150w would simply not penetrate to the bottom of the tank. But with either system going for just par would look extremely ugly and yellow.

 

well here is a blanket statement that is not true, let's try to avoid those

 

You started the blanket statements... I chose mine more carefully, if I made them at all to begin with.

 

Can you find a MH system that does not have to deal with heat issues? Mh most often requires either a chiller or a massive set of fans complimented with a fair amount of top-off to replace evaporation. I only top off 2x as much in my 120g with T5 compared to my 18g with MH; now lets ask another math question... 120g is how much bigger than an 18g??? a bit more than 2x that is for certain.

 

But I do get off topic here don't I? Lets answer those MH questions and keep T5 out of it.

[filefish949]

oh I will have to look up the specs on current draw and par value, sanjay's site is great for that and you can get rated current draw for that... tell me you are kidding about a 18 watt disparity.. and lamps verry a lot. if you want to make a big stink about it, sure i will go dig all this up for you monday

 

Can you find a MH system that does not have to deal with heat issues? Mh most often requires either a chiller or a massive set of fans complimented with a fair amount of top-off to replace evaporation. I only top off 2x as much in my 120g with T5 compared to my 18g with MH; now lets ask another math question... 120g is how much bigger than an 18g??? a bit more than 2x that is for certain.

 

 

you are more than welcome to come over and see mine any time i am available. i run 2 250MH 8" off the water 14 hrs a day I have a jbj 1/10 chiller which rarely runs and probably do not need it, yes i have a 8" fan on my sump temp controlled and it runs about 1/2 the time in the day and 1/4 of the time at night. the halides each have a 2" fan on them it is a 100 gallon tank my evap is ~ 1 gallon a day, I refill a 5 gallon bottle of lime water every 4 days or so

 

it is a serious invite, I love showing it off

Edited December 30, 2007 by filefish949

[Juanhunglo69]

I am going to jump in here about the whole evaporation issue. Sometimes evaporation has nothing to do with lighting or heat at all. I was evaporating about 1.5-2 liters a day a few months ago in my current setup. I made a change in the return pump from the fuge, I went with more GPH and now evaporate twice as much. This was apparent overnight not in weeks. It started evaporating up to 3 liters a day. I haven't changed anything else. I am running a 250 watt MH. So lighting and heat are not the only factors in evap.

[shaggydoo541]

Very true, many other issues can cause an increase/decrease in evap... surface area of the water exposed to air, ambient temp of your house, etc. Honestly though most tanks with MH need to deal with heat in some way and that is just a fact. Whether you just have a chiller for backup or an extra set of fans ready to turn on when/if necessary. If you have a MH system and you are not prepared for the extra heat (especially in the summer) you have a very high chance of frying your tank. Since this thread is about answering MH questions I feel it is very appropriate to address this heat issue especially since in a nano your temp can spike in a hurry. I know... I almost killed my tank when I first put on my 250w MH over my nano. I hit 90 degrees before I even knew what happened. Luckily a simple large room fan was all that was needed to keep it under control.

 

I'd love to come see your tank, as visiting other setups is always interesting to me. I'm constantly amazed at the variety of setups in this hobby and you can have success in a wide variety of ways. You don't by any chance live in UT? If not I'll have to take a rain check and ask that you post pics of your setup... do you have a thread showing your tank? I'd really like to see it.

[filefish949]

Very true, many other issues can cause an increase/decrease in evap... surface area of the water exposed to air, ambient temp of your house, etc. Honestly though most tanks with MH need to deal with heat in some way and that is just a fact. Whether you just have a chiller for backup or an extra set of fans ready to turn on when/if necessary. If you have a MH system and you are not prepared for the extra heat (especially in the summer) you have a very high chance of frying your tank. Since this thread is about answering MH questions I feel it is very appropriate to address this heat issue especially since in a nano your temp can spike in a hurry. I know... I almost killed my tank when I first put on my 250w MH over my nano. I hit 90 degrees before I even knew what happened. Luckily a simple large room fan was all that was needed to keep it under control.

 

I'd love to come see your tank, as visiting other setups is always interesting to me. I'm constantly amazed at the variety of setups in this hobby and you can have success in a wide variety of ways. You don't by any chance live in UT? If not I'll have to take a rain check and ask that you post pics of your setup... do you have a thread showing your tank? I'd really like to see it.

 

I never did start a thread on the display tank, i should, I have done a lot of cool things to it.. completly ot, but IMO, giant return pumps and skimmer pumps are the worst offender when it comes to heating a tank

 

my brother lives in sandy ut, I get out there every few years, are you anywhere neer sandy?

[nu2reefva]

I am going to set up a custom DIY 29 gallon and want some assistance on lighting i was thinking of going with 2 T5 actinics and one MH the problem is I do not know anything about MHs and want to know the best wattage.

[SPS20]

I am going to set up a custom DIY 29 gallon and want some assistance on lighting i was thinking of going with 2 T5 actinics and one MH the problem is I do not know anything about MHs and want to know the best wattage.

 

It depends what you are trying to keep, but I would think that a 150w DE or 175w SE setup would do the job just fine in your case. If you intend to keep very demanding SPS low in the tank, you might consider going with 250w, but even then, I think you would be fine with 150-175w. Since you are using actinics, I would suggest going for a lower-kelvin MH bulb, 6500-10,000k. Generally speaking, you get more PAR per watt with such bulbs. One exception to this is the Iwasaki 175w 14k bulb. It is a very high-PAR bulb with a nice bluish-white color, and is arguably the 'best' bulb available in this wattage range.

 

If you are planning on keeping LPS and softies, then I wouldn't worry so much about PAR, as they just aren't as demanding in the light category, generally speaking. Of course, there are exceptions.

 

Avoid the XM 15k 150w bulb at all costs. It is, bar none, the absolute worst MH bulb I have ever seen. It is so low on PAR that some 70w bulbs put out more usable light. Corals wither under it. I wouldn't use those bulbs to jam old food into my garbage disposal, as it would be an insult to the old food. I find the low quality of that particular bulb to be especially odd, as their 10k and 20k bulbs are good bulbs, and come highly reccomended.

 

So, the short answer: go for 150-175w, avoid the XM 15k 150w bulbs.

 

- Josh

[Ocho Cinco]

I have the aquapod 24 150 Halide. I got a clam the other day and was planning on placing it on rock higher in the tank so it gets more light. The second day I had it it attached it self to the rock. The next morning it kept jumping off the rock. Everytime I move it up it will jump again. Should I just keep it low (where it keeps jumping to)? The bulb is a year old but I will be replacing it shortly. Also on ebay I found the correct bulb I need for like $20. Does anyone know much about these?

[Chipsreef]

What brand bulb are referring to? Cheap bulbs on ebay are just that, cheap. Lots of options for 150w mh bulbs, just figure out what kind of bulbs will run on your particular ballast.

Edited January 31, 2008 by Chipsreef

[clifford513]

What brand bulb are referring to? Cheap bulbs on ebay are just that, cheap. Lots of options for 150w mh bulbs, just figure out what kind of bulbs will run on your particular ballast.

What is your experience?

[reefitup]

OMG

 

I just read this ENTIRE thread and you're telling me it stops HERE?

 

haha

 

I just switched from the stock BC hood to a 150w Sunpod. From what I'm reading here... if I'm understanding it correctly...

 

 

If I went with a 6500k 150 HQI bulb, and supplemented my lights with say some form of PC Actinics, I would

 

A. Avoid that yellowish look that nobody (including myself) seems to like

B. Give it the crisper clean (mildly blue-ish) look that everyone seems to like with something like the Phoenix 14k

C. My corals would reap the benefits of the 6500k bulb and would actually grow better than with a 14k?

 

In my stock BC hood that's on my wifes tank, the guy at the store dropped it and busted the 10k bulb that comes with them, and tucked in a 8k (if memory serves me) bulb. Very yellow with it on by itself, but the Actinic bulb really brings the light to a nice bright (slightly blue) level.

[Chipsreef]

I have no experiences with those cheap bulbs over ebay. Knock off bulbs that may not hold spectrum or may not even fire for that matter. I just dont want anyone wasting there money, There should be lots of threads on RC maybe even a few here explaining just why those bulbs are poor choices.

Edited March 4, 2008 by Chipsreef

[RBuddha]

Wow, my thread is still around. Nice to see its helping people

[suppressive fire]

whats your thoughts on lighting for my 40 breeder (see signature) which will be mostly SPS.

2 250's se

2 175's se

both will have actinic vho 4 bulbs on a new IC660

[suppressive fire]

^^^????^^^

lol