# T5 vs PC?



## kzr750r1 (Jun 8, 2004)

Not to muddy the waters but are you using a canopy on each tank? There are options for retrofit or buying the premade fixture. What is your preferance? I started using the T5 a couple of years ago. Others swear by the PC. It's pretty much the same technology either way, just in a different bulb configuration.


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## kzr750r1 (Jun 8, 2004)

quilting chick said:


> I'm looking at T5 HO's, and PC's and it's such a toss up. It appears that there are more bulb choices for the PC's, so that's a plus for them. But are the T5's cooler than PC's, generally speaking? Any comments on bulb life? I need a new light setup for my 70 gal, and something for my 110 gal.
> 
> Terri
> 
> Terri


As a general rule I think they run cooler but I don't have any large PC so I could not compare. As for T5 bulb life 2y on my two 54w bulbs. There probably going to go soon, the ends are darkening. Better longevity then I expected.


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## quilting chick (Jul 14, 2006)

I don't have a canopy, or for that matter a fixture that would hold them. I figured on making canopies to match the stands that I just refinished. We're going to have both the 70 gal and my new 110 gal setup in the living room, so I am concerned about the heat gain.

Terri


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## Momotaro (Feb 21, 2003)

I have been very happy with the T5s I have over my 50G. So happy, in fact, that I will be replacing the PCs over my little 38G with a T5 fixture in the fall. My 75G is a bit wonky right now, but once things settle back down (or I tear it down), I'll do T5s there as well.

Maybe it is just me, but the T5 look brighter and seem to run cooler than the PCs. Store bought fixtures are thinner and sleeker, too!

Mike


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## kzr750r1 (Jun 8, 2004)

If they both live in the living room it's probably best to run the canopy. Reason being the light bleed to the rest of the room is pretty substantial if using a hanging fixture. Even with only 2 54w T5 my fiancé is annoyed by it watching movies in the living room. I shut em down at times and it’s only whacking my light schedule out one hour or so. No big deal, best to keep the peace.

My preference is open top and hanging fixtures, in fact my whole setup is open since the stand is steel with no covers what so ever.

There are several companies that set up a nice retrofit kit or full on fixtures.

The next step is to decide what you’re going to grow to decide how much light you want over these nice size tanks.

Keep in mind the more light set over any water column the more prolific the growth.
So general rule is
High light = Lots of ferts and lots of trimming more often. Depending on the ballast configuration you can set up a 10 hour cycle with all 216w for the whole cycle. Or add another timer and run the ballasts at different staggered time schedules. Big deal is flexibility needs to be build in for adjustments.

Med light = Less ferts and trimming than High Light. Plants that prefer more than you’re providing will stretch out a bit and not color in fully. Still enough to grow a lot of plants well and have a great looking scape.

Low light = Even less ferts and in some cases just WC and that is it, trimming is minimal. It all depends on the plants selected but several do great with no contact with the substrate or those that do grow great with the proper root tabs or soil sub substrate.

Best of all with the T5 and the PC is the reflectors. Really helps turn all the light into your tank. The kicker for me was the heat issue and I loved the Tek Light look so it was an easy sell. Just keep your options open. At this point I’m tempted to go to a new fixture with twice the bulbs so they can be on staggered schedules. Hindsight is 2020 for most and we live and learn.

Check these guys out or T5 stuff and a bit of PC
http://www.specialty-lights.com/

AH is an awesome co for retrofit PC stuff. Just picked up the 2x13 Deluxe and couldn’t be happier.
http://www.ahsupply.com/


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## avillax (Jan 16, 2005)

Hello. I am going to tell you about T5 as I am a pro on the reefkeeping hobby.
T5 are newer technology, is totally proven over and over by experience and in coral reef forums, that thre is no comparission between t5 and pc. T5 are much more brighter than PC, just so that you know 3x54 watt t5 are brighter than a 200watt metal halide, but only if they have independent parabolic reflectors each t5 tube. IF not then they are a bit less powerful than a 150watt metal halide.

Also t5 last 2 years before you need to change them. Oh and they need less energy, many people think pc are more powerfull because of the wattage, but wattage is becoming a very old innacuarate rule in this hobby. What matters is intensity, and t5 are way more intense.

The only problem is that the smaller t5 that I have seen, are the ones used on dymax lamps. and are 50cm long, so it would be hard to fit them under a jbj nano cube hood. Although I have seen nanocustoms using t5, a smaller kind.


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## endparenthesis (Jul 13, 2004)

As far as I knew (and I could easily be wrong), PC was just T5 bent into a certain shape.

But what I've never gotten confirmed was whether PCs are T5s or HO T5s. I thought they were just T5s, in which case it would make sense for HO T5s to be brighter of course.


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## quilting chick (Jul 14, 2006)

So many decisions...... I'm reading up on ODNO now. Wish I could say that money was no object, but I've always been pretty prudent with my money. I don't mind paying more for something up front so that I don't end up replacing something later (and spending more money doing so.) I'm really leaning to the T5 HO's.

Terri


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## Canoe2Can (Oct 31, 2004)

endparenthesis said:


> As far as I knew (and I could easily be wrong), PC was just T5 bent into a certain shape.
> 
> But what I've never gotten confirmed was whether PCs are T5s or HO T5s. I thought they were just T5s, in which case it would make sense for HO T5s to be brighter of course.


Close. A PC is actually a T6 bent in half. But what's an 1/8 of an inch among friendly lamps?

And yes, PCs are high output lamps. They run much higher Wattages compared to normal flourescents. The idea of HO lamps is basically just that they put out more light in less space than a NO. To do that, they all require electronic ballasts.

As to the original question, I think T5s are better all around. Because of the shape of PCs, they will have more restrike than a thinner, straight T5. Throw in the good reflectors, and you have a more efficient lamp. That said, both have proven their effectiveness and either will work.


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## Momotaro (Feb 21, 2003)

Great discussion!

Not a hijack, but something related.

I have my 38G with a Coralife fixture (2x65W for 130W total - 3.4WPG). I am thinking of swapping it out for a T5 fixture (2x24W for 96W - 2.5WPG). 

I think with the brighter T5s and the better reflector I should be fine, but I am very interested in the opinions of everyone else.

Mike


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## avillax (Jan 16, 2005)

can't believe you guys are still thinking pc are bent T5. My coral reef was lighted with 384 watts of PCs and it wasn't enough, corals were growing very slow and not opening to much.

Then I changed to a 315 watt T5 lighting system, and everything started to grow wild, and corals opening much more, my bubble tip anemone even moved to a lower level, it is much brighter, and they last 2 years, instead of 1 year only.

If you don't believe me, go to the www.reefcentral.com forum and do some research on the lighting and other equipment forum. You will find out how powerful t5 are. In fact, for reefkeeping purposes PCs are almost obsolete.

2x t5 in a nano reef, would generate more light and more consistent over time, than 2xPC. And the 2xt5 would take the space of 1xPC.

But as I said, the smallest t5 I have seen is 50cm long, but think nanocustoms have smaller, ask them what is better, they will go for the T5 without thinking twice.


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## avillax (Jan 16, 2005)

Momotaro said:


> Great discussion!
> 
> Not a hijack, but something related.
> 
> ...


Go for the t5, the problem in this freshwater forums is that people still use the old lighting rule about WPG. That used to work for PCs and Fluorescents, but it doesnt apply for T5 or metal hallide, because these units are just much more brighter. 

In fact if you have for example 100 watt Metal Halide bulb, that would be brighter than 3.5 x 65 watt PC.

The T5 fixture you wanna buy, might have less wattage, but it is much brighter, therefore you will get better grow and more light for a cheaper electricity cost.


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## Rex Grigg (Dec 10, 2002)

avillax said:


> can't believe you guys are still thinking pc are bent T5. My coral reef was lighted with 384 watts of PCs and it wasn't enough, corals were growing very slow and not opening to much.
> 
> Then I changed to a 315 watt T5 lighting system, and everything started to grow wild, and corals opening much more, my bubble tip anemone even moved to a lower level, it is much brighter, and they last 2 years, instead of 1 year only.
> 
> ...



How much of the difference was due to reflectors?


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## quilting chick (Jul 14, 2006)

If the WPG rule doesn't really apply to T5HO, and I can see why it wouldn't, then how much light would you put over a 70 or a 110 gal? Both are 24" deep. It really sounds like T5 is the way to go.

Terri


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## Brilliant (Apr 11, 2006)

If you look in the stickies the WPG rule is "de-throned" IIRC it lays more importance on something called PAR.

For me PC was an upgrade from the OEM fluorescent fixture. As I fell deeper and deeper into the plantedtank and little bit of the reeftank thing I leaned towards something else. I opted for metal halides on my last upgrade.

I do have an Coralife Aqualight T5 fixture and I like it but for some reason I dont think its the same T5's people are talking about here.

I would vote for T5


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## attack11 (May 5, 2006)

par (photosynthetically active radiation) are the wavelengths for photosynthesis. it's the only aspect of lighting that really matters when growing plants or coral. kelvins is for your eyes, and can be important for aesthetics.


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## avillax (Jan 16, 2005)

When T5 first came out many years ago, their intensity was lower than today's T5s, in fact I believe that there are still some T5 that are less intense and are used for applications other than aquariums.

As for the question about how many t5s would be necesary to light a 70 or a 110 gal tank, it depends on factors such as the length of the tank, T5s come on the same lengths as PCs, so you choose the size depending on the size of the tank, now for the width of the tank, I would say a 15.7 inches wide tank would need 3x T5 tubes. or 2x T5 tubes with independent parabolic reflectors.

Also T5 light has the ability to penetrate the water column much better than PC's, in fact they are almost as MH for this purpose. For freshwater tanks that are normally not as deep as marine systems, I wouldn't worry, I'm pretty sure T5 can reach the bottom with no problem.

Now as for how much different there is between reflector vs no reflector, see this article, it will make you go to the store and buy T5 right away:

http://www.sunlightsupply.com/aquarium/products/t5reflectcomparo.shtml


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## kzr750r1 (Jun 8, 2004)

Brilliant said:


> If you look in the stickies the WPG rule is "de-throned" IIRC it lays more importance on something called PAR.


What I keep trying to remember. 



Brilliant said:


> I do have an Coralife Aqualight T5 fixture and I like it but for some reason I dont think its the same T5's people are talking about here.


NO vs HO 4' T5 NO=28w HO=54w



Brilliant said:


> I would vote for T5


Yes with the proper versions of T5 and reflector.



attack11 said:


> par (photosynthetically active radiation) are the wavelengths for photosynthesis. it's the only aspect of lighting that really matters when growing plants or coral. kelvins is for your eyes, and can be important for aesthetics.


Thanks for the link attack. Are we still sure yet that kelvin is only for the eyes? I'll be interested in Momo's 37g project just changing from the 9000K CF setup to a 6500K T5 setup. His concern was the bylxa seemed to color up with the additional red from the CF.


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## Zulu (Aug 18, 2005)

Power Compact bulbs get more efficient as they get longer. The 36" 96 watt PC is MUCH more efficient than the shorter 65 watt PCs. The new 48" 130 watt PC setup is the most efficient.

To repost from an old re-post of mine stolen from some guy somewhere else;


disclaimers are:

- watts/gallon is, at best, a marginal rule of thumb
- watts/gallon makes no comment on the light wavelengths present for chlorophyll activation or aesthetic viewing of your plants and fish
- watts/gallon does not account for tank depth or area of coverage
- watts/gallon does not account for bulb efficiency
- watts/gallon is mired in word-of-mouth confusion and does not readily account for technological advances in lighting

Different bulbs have different specs and you should research the products you are buying. If a manufacturer won't provide the specs, then don't buy their product.

*Comparison of Sylvania Bulbs to Help Show Differences Among T12, T8, T5, T5HO, and CF Lighting*

NOTE: Sylvania does not make a 96w 36" CF bulb - data is from a generic, probably Panasonic, bulb

*Standard T12 Lighting*
bulb: F30T12/CW/RS
power: 30w
length: 35.78"
life: 18000 hrs.
av. lumens: 1870
lumens/watt: 62.3

(note: there are 3' supersaver versions of T12 that use 5 less watts and have an av. lumen output of 1636 - not worth comparing.)

*Standard T8 Lighting*
bulb: FO25/730
summary for this bulb: 18.5% more economical for similar light output at the same bulb length
power: 25w
length: 35.78
life: 20000 hrs. (11.1% better)
av. lumens: 1845
lumens/watt: 73.8 (18.5% better)

For this T8 bulb, the difference compared with T12 is that it uses 5 less watts to produce equivalent light (19% savings) with a bulb diameter that is 33% smaller, which means that more of them will fit in a hood. This bulb also has a longer rated life.

*Standard T5 Lighting*
bulb: FP21 (PENTRON T5)
summary for this bulb: 30-50% more economical for the similar light output at the same bulb length
power: 21w
length: 34"
life: 20000 hrs. (11.1% better)
av. lumens (at 25c): 1758
lumens/watt (at 25c): 83.7 (34% better)
av. lumens (at 35c): 1953
lumens/watt (at 35c): 93 (49% better)

For this T5 bulb, the difference compared with T12 is that it uses 9 less watts to produce equivalent light (30% savings) with a bulb diameter that is almost 60% smaller, which means that more of them will fit in a hood. This bulb also has a longer rated life.

*T5 HO Lighting*
bulb: FP39/841/HO (PENTRON T5 HO)
summary for this bulb: 15-34% more economical for 50-75% more light output at the same bulb length.
power: 39W
length: 34"
life: 20000 hrs. (11.1% better)
av. lumens (at 25c): 2803
lumens/watt (at 25c): 71.9 (15% better)
av. lumens (at 35c): 3255
lumens/watt (at 25c): 83.5 (34% better)

For this T5 bulb, the difference compared with T12 is that it uses 9 more watts (30% more energy) and produces 50-70% more light. As above, the bulb diameter is 60% smaller and the bulb has a longer rated life.

*Compact Fluorescent - Twin Bulb - Similar Wattage*
bulb: FT36DL/835 (Dulux L) (uses T5 bulb diameter for a total width slightly wider than T12)
summary for this bulb: 11% more economical for 33% more light output at less than 1/2 the same length.
power: 36W
length: 16.6"
life: 12000 (33% worse)
av. lumens: 2494
lumens/watt: 69.3 (11.2% better)

For this CF bulb, the difference compared with T12 is that it uses 6 more watts (20% more energy) and produces 33% more light. The bulb diameter is slightly wider than a T12 (+.5") and the bulb has a shorter rated life. However, in this case, the overall bulb length is less than 1/2 as long.

*Compact Fluorescent - Twin Bulb - Higher Wattage, Slightly Longer*
bulb: FT55DL/835 (Dulux L) (uses T5 bulb diameter for a total width slightly wider than T12)
summary for this bulb: 20% more economical for 121% more light output at 60% of the same length.
power: 55W
length: 21.1" (still much shorter overall)
life: 12000 (33% worse)
av. lumens: 4128
lumens/watt: 75 (20.4% better)

For this CF bulb, the difference compared with T12 is that it uses 25 more watts (83.3% more energy) and produces 121% more light. The bulb diameter is slightly wider than a T12 (+.5") and the bulb has a shorter rated life. However, in this case, the overall bulb length is 60% of a 30w T12.

*Compact Fluorescent - Twin Bulb - Higher Wattage, Similar Length to 30w T12*
bulb: Generic 96w CF (uses T5 bulb diameter for a total width slightly wider than T12)
summary for this bulb: 20% more economical for 333% more light output at 95% of the same length.
power: 96W
length: 33.85" (still slightly shorter overall)
life: 12000 (33% worse)
av. lumens: 8100
lumens/watt: 84.4 (35.4% better)

For this CF bulb, the difference compared with T12 is that it uses 66 more watts (220% more energy) and produces 333% more light. The bulb diameter is slightly wider than T12 (+.5") and the bulb has a shorter rated life. The overall bulb length is roughly equivalent to a 30w T12 (95%).

...and just for laughs:
*Double-ended Metal Halide HID*
bulb: HQI-DE250/NDX
summary for this bulb: This bulb is roughly equivalent in efficiency to 9 30w T12's with 756% more light output than a single 30w T12 which it accomplishes in 6.5" of space with a lower life expectancy (but similar replacement interval).
power: 250W
length: 6.5"
life: 10000(45% worse)
av. lumens: 16000
lumens/watt: 64 (2.7% better)

For this HID bulb, the difference compared with T12 is that it uses 220 more watts (733% more energy) and produces 756% more light. The bulb size is much smaller than T12 and the bulb has a shorter rated life. The point of using this bulb is not increase lighting per area, since it produces tremendous light (and heat) in a relatively small space as compared with linear or compact fluorescents.

So, given reasonable room with a dual T12 36" x 8" hood to mess around with reflectors and bulb positioning, and assuming you have the correct ballasts and fixtures, the following arrangements should be possible:

bulb: total wattage, total visible light output, watts/gallon, lumens/gallon
(note: watts/gallon and lumens/gallon have only marginal bearing on chlorophyll activation and are calculated based on Iggy's tank size of 65 gallons)
------------------------------------------------------------------------
*Baseline = Standard T12:*
Dual T12 30w: 60 watts, 3740 lumens, .92 w/g, 57.54 l/g
(note: "Lumen Groups" below based on a 1.0
lumen rating of 3740)
------------------------------------------------------------------------
*1.3x-1.5x Lumen Group:*
Triple T5 21w: 63 watts, 5274 lumens, .97 w/g, 81.14 l/g
Dual CF 36w: 72 watts, 4988 lumens, 1.11 w/g, 76.74 l/g
Triple T8 25w: 75 watts, 5535 lumens, 1.15 w/g, 85.15 l/g
------------------------------------------------------------------------
*2x+ Lumen Group:*
Quad T5 21w: 84 watts, 7032 lumens, 1.29 w/g, 108.18 l/g
Single CF 96w: 96 watts, 8100 lumens, 1.48 w/g, 124.62 l/g
Dual CF 55w: 110 watts, 8256 lumens, 1.69 w/g, 127.02 l/g
Triple T5 HO 39w: 117 watts, 8409 lumens, 1.8 w/g, 129.37 l/g
------------------------------------------------------------------------
*3x+ Lumen Group:*
Quad T5 HO 39w: 156 watts, 11212 lumens, 2.4 w/g, 172.49 l/g
------------------------------------------------------------------------
*4x+ Lumen Group:*
Dual CF 96w: 192 watts, 16200 lumens, 2.95 w/g, 249.23 l/g
Quint T5 HO 39w*: 195 watts, 14015 lumens, 3 w/g, 215.62 l/g
Metal Halide 250w: 250 watts, 16000 lumens, 3.85 w/g, 246.15 l/g
------------------------------------------------------------------------
*note: This is obviously less practical for a number of reasons, but I have included it to help illustrate the trade-off point between HO and CF.

As you can see from the above, watts/gallon and lumens/gallon (visible light output) do not track. The watts/gallon rule is based on using STANDARD FLUORESCENT LIGHTING and is somewhat divorced from specifying what wavelengths of light are present for viewing your fish and plants, for activating chlorophyll, and for reaching varying tank depths at equivalent gallonage. So, at 4 watts/galllon using this rule, ignoring the fact that it has serious flaws, you would have 260 watts of standard T12 lighting, requiring 8.7 (9) 30w T12 bulbs positioned over your tank for a total bulb width of 13.5" not counting spacing and a total visible output of 16269 lumens (250.3 lumens/gallon).

Comparing this to an equivalent output from CF, you can see that with two 96w CF's, a bulb width of only 4" (not including spacing) is required with a power savings of 36% and with substantially less heat dissipation. You will also note that T5 HO may offer some power savings depending on how much light you want.

HID would be the same as the 9 fluorescents with much greater heat dissipation. The single 96w CF bulb would appear to be a comparitively good performer (vs. 55w CF and T5 HO).

Beyond illustrating these comparisons, however, it would be better to consider how much of what wavelengths of light were being distributed over a given area at a given tank depth!

The other thing to remember is that different bulbs have different specs. There are bulbs from other manufacturers that have different efficiencies and outputs. I used all Sylvania bulbs (except the 96w) to try and keep things consistent within a single manufacturer. Different lengths of the same bulb also have different efficiencies. These are other major flaws with "watts/gallon."

As for replacement life, regular fluorescents generally have poor lumen maintenance. They may lose 25-40% of their output over their rated life. CF lighting has better lumen maintenance (10-15% loss), but also a shorter life. CF life is 2/3 of T12's and a T12 may lose 25% in the first year, whereas CF will only lose 15% over its total life.

So, while the life is shorter, the bulb decays less, so even if you only replaced your CF bulbs every 2-3 years, that could be equivalent to replacing a T12 every 6-12 months, depending on the bulb specs involved. However, you won't break even on the cost of CF vs. T12, but you're also getting a lot more light, so who cares? Base your replacement timeframe on the specific decay spec for your bulb, not a rule of thumb. It's crazy to replace CF's every 6 months! You would replace HID once/year since the lumen maintenance is relatively poor (40% loss over rated life).

I hope this illustrates the comparison a little better. As you can see, to create your lighting scheme, you can choose among light output, efficiency and size to try and maximize your hood space to achieve your specific lighting goals per tank area. Once again, remember that the information above does not necessarily indicate how much light is getting into your tank at what depth or area or how much of that light is appropriate for plants (wavelengths produced).

Lumens are an indication of light as seen by humans, not plants, but I used it to try and help you see the differences in bulb output. Also, there is still additional variance bulb-to-bulb, since twin-tube bulbs like CF block some of their own light due to the tube proximity and there is more than one way to implement a reflector. The tighter the bulbs are packed, the less efficient they will be in combination with a reflector.


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## inkslinger (Dec 28, 2003)

i also got a 110g tank with canopy ,i have 3 sunlamp supply ballasts with 6 t5 ho 54w 48" . i use a pice of ply wood 11/4 inch thick and painted it white and mounted the 3 ballasts on one side , the other side i mounted the stand offs w/waterprof encaps , i stager each one w/refectors end to end , i also drilled a small hole next to each end cap to run the wires thur and mounted the whole thing to the canopy , so all you see is lights and 3 long power cords, it does add a little more weight to the lid and looks good. this sould worke with pc too.:fish:


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