Why are T5s better than power compacts?

[lakwriter]

I've been considering upgrading my lighting (i currently have normal output flor.). I've had some people tell me to definetly go t5 and others tell me the difference is negligible considering the price difference.

Given the same wattage, why is T5 so much better? More energy efficient? more/less heat output?

Or is it just that t5s are more $, so they must be better.

The reason for the upgrade is that next year I'd like to get a coral or 2. Just looking to keep stuff like bubble coral, frogspawn, 'shrooms, maybe a toadstool.

Thanks!

[lakwriter]

^^

[salty55]

in my honest opinion. i haven't figured out why people rave about
T5 so much, and cut down pc's. it looks to me like 100 watts of p.c. flourescents are just as good as 100 of T5 flourescents. if there are some major difference besides personal preference, someone please tell. because i would really like to know also.

[RichConley]

Originally posted by salty55
in my honest opinion. i haven't figured out why people rave about
T5 so much, and cut down pc's. it looks to me like 100 watts of p.c. flourescents are just as good as 100 of T5 flourescents. if there are some major difference besides personal preference, someone please tell. because i would really like to know also.

T5s have almost twice the output per watt as PCs. Combine that with the fact that its very easy to create efficient reflectors for T5s, and impossible for PCs, and you end up with, watt for watt, T5s having almost 4 times the output of PCs.

Because of the poor shape of PCs, they get overly hot, and because of that, run less efficiently, and have shorter life spans.


Basically, you get better bulb selection, 2-3 times the life span, and 4 times the light with T5s.

[salty55]

ah, so now we know. thanks

[mope54]

that said, PCs are more than sufficient for you lakwriter.
If you already have investment in PC lights, I don't see the benefit of upgrading for you. Certainly not until your bulbs are out...I keep the same thing and I didn't feel the need to upgrade when I decided to buy new bulbs.

I bought expensive bulbs from a store, but I could have easily bought $10 PCs and there's no way to justify a whole new setup over a $40 expenditure.

[salty55]

but anyways, yes pc's will work for you. i have pc's on my 55. i currently have a frogspawn, xenia, and shrooms. all doing great.

[Icefire]

It's like going T8no.
They are efficien lm/watts but having 8 bulb and 320w of t8 when you get the same with 2-4 bulb, 108-216w of t5

[Musho3210]

Run cooler and bulbs can last longer, thats all i know.....

[Scythanith]

here is a simple comparison:

with 4 x 55 watt PC's (bulbs ~1 month old)



with 6 x 39 watt T5HO's on SLR's(brand new & same camera settings as the above photo):



adjusted camera settings:



my reds and pinks are much more vibrant and my frogpawn & hammer as well as the rest of the corals (aside from my pink echinphyllia) are LOVING it!

Cheers,

Scott

[IPT]

I was getting fair growth o some SPS but am acclimating to t5's right now. Aready I am seeing color gains from them verse the PC's (more purple and blues instead of brown). My shrooms and Yellow polyps on the other hand are not liking it. 200 watts PC now 195 watts T5's. The T5s are clearly brighter. No comparison. The color is better as well.

[lakwriter]

OK, so now I know. How many watts should I get to go t5 and keep low to medium light corals? the tank is a 29 gallon, 30" long, 18" tall. So 24" bulbs are the biggest I could go. Or what # of lumens would I want if I shouldn't be shopping by watts?

[n00b mariner]

T5 is the diameter of the bulb. Power compacts are the same size so therefore unless the shaping of the tube has drastic effects on the performance(i dont believe it does apart from the heat issue because the are closer together) then they are the same ^^

[RichConley]

Originally posted by n00b mariner
T5 is the diameter of the bulb. Power compacts are the same size so therefore unless the shaping of the tube has drastic effects on the performance(i dont believe it does apart from the heat issue because the are closer together) then they are the same ^^

Nope. Completely 100% wrong.


T5 straight bulbs are designed to run at a different temperature than Pcs, different voltages, and use different phosphors. In short, the only thing they have in common is tube size.

One of the major differences is that T5s are designed to be most efficient at 95 degrees. PCs are designed to be most efficient at about 70 degrees. Has anyone ever seen a 70 degree light hood?

[Musho3210]

Im pretty sure PC's are T3's...

[n00b mariner]

So are these prosecutable under the Trade descriptions act? :-

http://www.1st4aquatics.com/index.as...YCAT&catid=175

[RichConley]

Originally posted by Musho3210
Im pretty sure PC's are T3's...

I think the ones we use for reefs (96w, 65w, etc) are T5, the screw in ones are T3.

[Musho3210]

ok then im wrong, maybe those screw in PC lights that replace incandescent are T3....

[RichConley]

Originally posted by n00b mariner
So are these prosecutable under the Trade descriptions act? :-

http://www.1st4aquatics.com/index.as...YCAT&catid=175

No. Theyre Power Compacts, which are T5.


When we say "T5" we are talking about T5 Linear bulbs.

[n00b mariner]

But they are power compacts, no? and t5 is the tube size, no?

[hahnmeister]

Originally posted by mope54
that said, PCs are more than sufficient for you lakwriter.
If you already have investment in PC lights, I don't see the benefit of upgrading for you. Certainly not until your bulbs are out...I keep the same thing and I didn't feel the need to upgrade when I decided to buy new bulbs.

I bought expensive bulbs from a store, but I could have easily bought $10 PCs and there's no way to justify a whole new setup over a $40 expenditure.

I did a cost comparison a while back in one of these threads, and actually, the numbers showed that even if you already have PC's, switching to an equal wattage T5 setup would pay for itself in the first 2 years.

The T5 bulbs themselves are better for starters. Their phosphors are more able to withstand heat, and therefore last longer... much longer. The average PC bulb loses the same amount of output in 9 months that it takes a T5 2 years to lose. The phosphors are also brighter... about 50% higher output per watt than PC.

That doesnt sound like much, but then consider the slim profile of T5s, which allows for a very important and effective individual parabolic reflector per each bulb with T5s. The end result is a bulb with over 2x the output per watt of PCs, almost 3x in most cases.

That being said, even though T5s are a bit more expensive, you can use less wattage with them to get the same result as with PCs, and with them also comes the savings in bulbs. The average per T5 bulb is about $20 (some actinics cost more, but you can also get GE daylights for $10, so it evens out the spread), while the average PC bulb is about $30 for one even halfway decent, often times, more. The PC bulb needs replacement 2.6 times in the same time it takes one set of T5s to wear out (not to mention, watt for watt, you will need less bulbs).

A 55g for instance, with a 4x65wattPC fixture (a rather common combo years ago) could be illuminated now by just 2x54wattT5 bulbs, and get just as much light, if not more.

Many go ahead and do 4x54wattT5s over a 55g, which does double the light, and still ends up being the more economical option in the long run.

The cost of a 4x65wattPC fixture to maintain for 2 years: at 12 hours per day, .10 per kwh of electricity: $114 per year. Bulbs @ $25 each, 4 @ 2.66 times in 2 years: $266! Yep, with PCs the bulbs is where they get you. I have heard many LFSs sell customers these units even now because they know that the return on the bulbs later will be even greater. So thats about $494 in running costs alone for 2 years. If you are in Cali, or somewhere that elec is higher... well... add it up! There is also the heat output, and its contribution to A/C costs, but thats too hard to find out.

Then there is T5:
A retro for 2x54wattT5s: $249. This is equal to the light output of the 4x65 PC setup, but you could go 4x54 for just $50 more (Tek2 retros from Reefgeek). Either way...

Then electricity: considering the output, many T5 users can run the bulbs for less hours then PC's... more like halides with a daily photoperiod of about 8 hours is what I run mine at... and I am leaving 1/3 my bulbs off these days because some corals are still getting too much (6x39wattT5 over a 40B). But lets say 9 hours per day, over two years at .10 per kwh again... thats $36 per year for 2x54wattT5s at 9 hours per day, or $48 at 12 hours per day. For 4x54, just multiply by 2, but you would for sure be running only 8 hours per day... so it evens out.

Also, for lights, you are talking an average replacement cost of $20 per year (1 bulb per year = 2 bulbs per 2 years) on a 2x54watt setup, and $40 for a 4 bulb setup.

As you can see already, the numbers are low.

The setup is the major hit, but T5s pay for themselves fast.

[RichConley]

Originally posted by hahnmeister
I
Then there is T5:
A retro for 2x54wattT5s: $249. This is equal to the light output of the 4x65 PC setup, but you could go 4x54 for just $50 more (Tek2 retros from Reefgeek). Either way...

ReefGeek has the 2x retros for $159. Theyre $249 if you want the icecap ballast.

[Musho3210]

The tek reflectors are very good, i use them on my freshwater 75 gallon.

[akabilly]

From my experience the T-5's are cheaper, last longer, run cooler and the PC hoods weigh almost twice as much as a comparable T-5 hood.
my .02

[pjf]

For efficiency alone, I recommend linear T5 lighting over PC lighting:
• PC or pin-based high-wattage compact fluorescent lamps (HW-CFL) generate ~60 lumens per watt: http://lightingresearch.org/programs...L-efficacy.asp
• T5 lighting produces 90-100 lumens per watt: http://www.lrc.rpi.edu/programs/nlpi.../lat5/pc1a.asp

Linear T5 tubes have additional efficiencies. When fitted with individual parabolic reflectors, more light will be directed into your aquarium that would otherwise be wasted.

The twin-tube design of PC lamps results in tubes absorbing light emitted from its neighboring tubes. Because the twin tubes are so close to each other, they cannot be fitted with individual reflectors. A significant portion of the light bouncing off a common reflector is absorbed by a PC tube.