# T5 vs MH HQI



## doubleott05 (Jul 20, 2005)

Please vote as if money was not an issue. (kinda funny cause there both pretty $$$)

im getting a new fixture and im wondering what the general public feels is appropriate or what they would vote for. 

this will be for a 90x45x45cm tank (approx 50gal)


choice one: 6x39w T5 --- 234watts/4.68wpg

choice two: 1x150w MH, 2x55w CF --- 260watts/5.2wpg 


im torn between the two

Thanks


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## doubleott05 (Jul 20, 2005)

thanks for voting pat

common people there are 29,000 users on here maybe a good 10,000 are active surely you want to vote and put your 2 cents in.


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## houseofcards (Feb 16, 2005)

Both will do the job very well, but I think the T5 setup is the better choice. No ballast to worry about, no heat, less energy. I'm assuming independent switches.


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## tanker (Jun 12, 2009)

A 150w MH is nice for a deep tank 60+cm tall. For a tank that is only 45 stick with the T5 or CF(less heat).


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## TAB (Feb 7, 2009)

MH no question.


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## freshyleif (Jan 9, 2008)

I don't know the life span of MH but T5's last along time. If you have 6(which is a lot of light for a 50g) then you have the ability to make your light color very depending on what you like,I might only go with 4 or 5. That being said I have a 75g that I have a hard time getting good light to the substrate in front for my foreground plants.


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## doubleott05 (Jul 20, 2005)

thanks guys. 

mh seems to get good depth penetration but washes out the colors cause its so intense/ but thats what the CF's are for to bring back the coloration and add a bit of power

T5 seems to give good rich color but lacks depth penetration


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## TAB (Feb 7, 2009)

freshyleif said:


> I don't know the life span of MH but T5's last along time. If you have 6(which is a lot of light for a 50g) then you have the ability to make your light color very depending on what you like,I might only go with 4 or 5. That being said I have a 75g that I have a hard time getting good light to the substrate in front for my foreground plants.


life span of T-5s is between 6-9 months before they go down hill really fast.

MH are about a year before they go down hill. replacing 6 bulbs at $15 each twice vs replacing one at $75.


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## Shurik (Mar 22, 2008)

TAB said:


> life span of T-5s is between 6-9 months before they go down hill really fast.
> 
> MH are about a year before they go down hill. replacing 6 bulbs at $15 each twice vs replacing one at $75.


I've heard about "going downhill" effect of any light bulbs too, but I also know it depends... My T5 are two years old and still OK - plants are growing as they used to, and this is what's important, the results, not the formal age of the bulbs. Right? (I got Hagen Glo T5). Or should they be replace them any ways? 
It would be nice to hear from people if there is a difference in the quality of particular bulbs by manufacturer, if it matters. 
I like this thread and would like to know more about MH and T5 difference for the future purchases too. 

Cheers!


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## doubleott05 (Jul 20, 2005)

tab i was thinking the same thing. only i though T5's were good for about 10 months but i knew they dont make it a year. 

i have been using MH since 2005 and they crap out pretty religously around a Year exactly. CF's are good for about a year as well.


you aint lying man bulbs are hella expensive.


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## doubleott05 (Jul 20, 2005)

Shruik i bet if you replaced your bulbs you would see a dramatic difference in the growth of your plants. the reason you think your plants are growing as usual is becuase youve become desensitized to the effects. meaning as the bulb depleats you dotn notice a difference cause its so subtle.

i bet if you bough new bulbs and put them in the same fixture as and old one it would be night and day


as far as the manufacturer thing goes: i know everybody has a preference but im not sure what it is. as for me i prefer 

Lights of America
ADA 
Coralife

IMO they have the best quality lights

Thanks for sharing everybody


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## TAB (Feb 7, 2009)

Shurik said:


> I've heard about "going downhill" effect of any light bulbs too, but I also know it depends... My T5 are two years old and still OK - plants are growing as they used to, and this is what's important, the results, not the formal age of the bulbs. Right? (I got Hagen Glo T5). Or should they be replace them any ways?
> It would be nice to hear from people if there is a difference in the quality of particular bulbs by manufacturer, if it matters.
> I like this thread and would like to know more about MH and T5 difference for the future purchases too.
> 
> Cheers!


If your happy, then don't replace them. if you want to keep your light "at its best" then you should replace them. All lights color shift and lose par over time. For me any drastic color shift and/or output less then 80% and its time to replace them. your paying for the power used, might as well get the most out of it.


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## doubleott05 (Jul 20, 2005)

i agree with TAB


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## houseofcards (Feb 16, 2005)

Not sure if I agree with the bulb cost analysis. I mean you will not be running, well I should say you don't have to run all 6 T5 bulbs all day, so one bank will only be used 1/3 or even 1/4 of the time as the other bank, thus extending their life. I think the cost difference is negligible.

Actually looking at your setup. Not sure you need 6x39. I think 4x39 would give you very little limitation.


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## ashappard (Jun 3, 2006)

house has a point about 6 vs 4xT5, 
both of your poll choices offer *bright* light.
I wont preach against it - I like bright light but it does often come with more work.

I cant say I agree with the earlier comment that MH 'washes out colors' but either way, both setups would be great for growing plants in your setup. The multi T5 would be my choice if it is a show tank, especially if you have the option to cut off one bank for part of the photoperiod.

I love growing under MH lights. One issue under MH-only lighting is that because it is a point source light you get the possibility of shadows cast by dense plantings. Having a combo fixture that includes MH and T5 or CF gives a better spread/scatter for even illumination. For viewing, it can make a more attractive display. If growout instead of layout is your goal, no worries - a cheap MH fixture is perfect. I lurk reefer sites and try to get their used fixtures. I dont care if the ballast works anymore, just if the reflector is high quality. I've found that low cost ( ~$20US) MH bulbs work just fine and have decent PAR and life (color shift and lost PAR) vs the $90US bulbs. way more cost effective.

lighting and CO2 are two areas not to skimp or settle for less. Cheap fixtures can be excellent but make sure they are still well made. A decent quality reflector is my main criteria. cheap ballasts can be overcome with third party replacements. its a pain to replace a reflector, and a bad reflector sours my opinion of a fixture and the manufacturer.


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## londonloco (Sep 25, 2005)

I'd like some clarification here on T5's "going downhill" after 8 mths. I've read over and over they last 5 - 7 years w/out significant loss of light. I've had both MH (on a reef) and now T5's (on planted tanks). I gave my MH lights away, tired of the electric bill and buying new bulbs every year to 18 mths (HQI bulbs). Not doubting here, just trying to learn.


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## freshyleif (Jan 9, 2008)

The twin tubes on a compact flourescent are actually the same as a straight tube T5, they are just bent tubes or in parallel. The way it was explained to me is that they don't last as long because they heat up more than the straight tube. The T # such as T8, T5 or T12 refers to the size of the glass tube.


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## londonloco (Sep 25, 2005)

freshyleif said:


> The twin tubes on a compact flourescent are actually the same as a straight tube T5, they are just bent tubes or in parallel. The way it was explained to me is that they don't last as long because they heat up more than the straight tube. The T # such as T8, T5 or T12 refers to the size of the glass tube.


Right, my understanding is CF's run hotter than T5's. But my question is why everyone in this thread is saying T5's only last a year. I've read over and over in other threads they last 5-7 years w/out any significant decrease in quality. I'm not meaning to hijack this thread...


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## doubleott05 (Jul 20, 2005)

right back to topic....

the reason i prefer high lighting is because i have noticed that when you get upto and over 4wpg (i totally believe in the WPG theory in tanks no taller than 45cm) that your plants dont get leggy and lacking. now i also know that ferts and other things play part in that but high light def helps prevent this. you also get better results in plant color.

i have had trouble understanding how one can grow great plants wiht just 3wpg. 


heres a new question:

do you think that you get better output from a T5 (150w value) or from MH (150w value) 
i dont care about spotlighting or illumination but as far as POWER goes. thats y i was asking about a 6x39w instead of a 4x39w in the T5 category.


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## TAB (Feb 7, 2009)

watt per watt MH puts out more light then T5s. its just much more concentrated.


on off cycles is what really does damage to bulbs, not the time on.( unless they get really hot, but thats another thread)


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## doubleott05 (Jul 20, 2005)

ok thanks TAB

i knew MH was still king


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## houseofcards (Feb 16, 2005)

I had a 46g setup for a while. Same high as your 50g with 2x96 CF bulbs and I no problem keeping nice tight carpet of HC and Hairgrass. So that was about 4.2 wgp with CF light. The only limitation was getting reds with that intensity and height.


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## doubleott05 (Jul 20, 2005)

house of cards ... to me with high light getting reds is much easier. can you explain how you had trouble getting your reds?


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## houseofcards (Feb 16, 2005)

doubleott05 said:


> house of cards ... to me with high light getting reds is much easier. can you explain how you had trouble getting your reds?


Purely a light intensity and height relationship. Although it was 4.2 wpg the CF lighting simply was not intense to get nice red stems. I don't think that would happen with T5HO.


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## doubleott05 (Jul 20, 2005)

oh i see you just werent getting the depth penetration you needed


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## baos (Jul 3, 2009)

I have 4 t5ho on a 90g. I have had plants flower, but not for very long. I now have a 400w MH on a 120g and am looking forward to seeing flowers in the future. By the way if you get a digital ballast(30% more cost) then your MH will have almost full color for it's entire life. However it's life will be significantly shortened instead of giving you months of useless color. You replace it when it burns out.


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## doubleott05 (Jul 20, 2005)

thanks baos


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## ashappard (Jun 3, 2006)

baos said:


> I have 4 t5ho on a 90g. I have had plants flower, but not for very long. I now have a 400w MH on a 120g and am looking forward to seeing flowers in the future. By the way if you get a digital ballast(30% more cost) then your MH will have almost full color for it's entire life. However it's life will be significantly shortened instead of giving you months of useless color. You replace it when it burns out.


I'll agree that electronic/digital ballast will help with color shift, but not sure about the bulb life statement. They start the bulbs in a more 'friendly' way, and seem to extend life not shorten it IME. I like the ice caps to replace old or sub-par ballasts in MH systems.

I get excellent flowering under 150W MH, for what its worth.


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## baos (Jul 3, 2009)

ashappard said:


> I'll agree that electronic/digital ballast will help with color shift, but not sure about the bulb life statement. They start the bulbs in a more 'friendly' way, and seem to extend life not shorten it IME. I like the ice caps to replace old or sub-par ballasts in MH systems.
> 
> I get excellent flowering under 150W MH, for what its worth.


That will be great if the $80 bulb lasts longer! I'm very new to it and I'm only going on what the hydroponics store told me. Longer life and full color sounds good.


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## TAB (Feb 7, 2009)

electronic ballast also generally don't put out as much light as thier mag counter parts. I've had both, I prefer the mag.


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## ashappard (Jun 3, 2006)

a cheap electronic ballast may not last long or perform well, and it's true magnetic ballasts will likely last forever. I have a pair of 250W mags that are over 10 years old and still going strong.

try the ice cap ballasts as a comparison. more efficient, they run relatively cool and I see better intensity and color from them. I use them to drive the cheap fishneedit bulbs and they work great. Or the $90 ADA bulbs, I've driven them with ice caps too but cant justify the bulb cost any longer.


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## doubleott05 (Jul 20, 2005)

surely more people wanna vote


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## tom855 (Feb 5, 2006)

I'd certainly cast my vote for HOT5s, but do plan to replace the bulb on a regular basis. It makes a visible difference if you let them in too long and then replace. They say 12-18 months but I try to replace mine on a 12 month cycle. And yes, they are pricey.

Tom 


.


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## doubleott05 (Jul 20, 2005)

thanks tom


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