T5 or T5-PC

[wozza]

Hi everone,

in sept this year i will have to move to go to uni and most likely put my current set up in to storage .
But i realy want to keep my two clowns and the BTA so i will just have to down size most likely tank size will be 24x12x15" and no longer have my 150w MH.

my question is what would be the most powerfull/best lights to keep my anemone under?

at the moment im looking towards the two following sets of lights

4x 55w 21" Marine White 14000k

or

Arcadia Luminaire T5Mx4 24

what do you think any other options?

cheers james

[Poseidon]

I would say the T5 for sure, but why can't you keep the 150W? It seems that size tank would be perfect for a single bulb.

[wozza]

you have got me thinking, the main reasion is bills, water, electric etc...
but if i got 150w of T5 it would the same as 150w MH drain on energy correct?

For some reasion in my head the MH drained more because its better!.

oh well i will just have to think of some way of having the MH over the tank because i cant hang from walls or clings because i would be renting, maybe extend the legs of my current invention.

[luke33]

Yes, i wouldn't worry about new lights, your 150 will do fine, and FWIW, i don't believe Mh's are better than t5's. They are both equal imo.

[ReefHog]

What makes T5 lamps better than the CF lamps? (i know technicaly they are both T5's) Is it all in the reflector?

[luke33]

The t5's are smaller in diameter and with good reflector's have much more par than a CF. They also run much cooler and are more efficient. Much brighter as well. There are also many different kinds. In order to keep sps on the bottom of a tank the sandbed needs to be at over 100par and t5's penetrate the water very well and many of the daylights with good reflectors have over 320par......they aren't even comparable to a CF. Hope this helps.

[ReefHog]

Are T5's really smaller? Arn't they the same diameter...just bent in the CF's?

[luke33]

T-5 means 5/8" diameter. They are very small. t-6 = 6/8" diameter. Yada yada. They don't make t5's over 60" because they are so fragile.....well, helios makes a 71" t5, but thats the only one i know of. Thats why individual reflectors ar eso important beccause they can reflect all the light off them, there's plenty of room since the bulb is so thin. Hope that helps a bit

[Ninong]

The t5's are smaller in diameter and with good reflector's have much more par than a CF.

T5's and compact fluorescents are both 5/8" diameter.

[Ninong]

Are T5's really smaller? Arn't they the same diameter...just bent in the CF's?

They're the same diameter.

[ReefHog]

I thought they looked about the same. I didn't use a caliper or anything though. After thinking about it, it seems to me that with a straight lamp (aka T5) a reflector could reflect the most possible light back into the tank. With a CF lamp, even with a good reflector, some of the light is directed back to itself on the "in" side of the bend. In other words 25% of the light is not reaching the reflector because half of the lamp itself is blocking it. Therefore, maybe T5's are 25% brighter that an equal watage CF. Does this make sence? Of coarse a typical CF is 65 watts and a comparable T5 is only 54 watts. So are 2 65 watt CF's the the same as 2 54 watt T5's? Has there been any comparasons between the two types of lights? Boy I wish I had room in my canopy for MH's.

[luke33]

Reefhog, your comparison isn't close. You should check out Grim at RC, he'd tell you all you need to know. A 54w t5 isn't even close to a 65w CF. The par put out by the cf isn't comparable to a t5 light. Most geisman and ati t5 lights will have over 320 par, which is great, even more than many MH's. I'm guessing a cf isn't even close to that.

[Ninong]

With a CF lamp, even with a good reflector, some of the light is directed back to itself on the "in" side of the bend. In other words 25% of the light is not reaching the reflector because half of the lamp itself is blocking it. Therefore, maybe T5's are 25% brighter that an equal watage CF. Does this make sence?

Yes, you're on the right track. This is why it is important that each individual T5 HO fluorescent lamp be mounted in its own individual parabolic reflector. This is very important if you want to realize the full potential of this lamp.

Of coarse a typical CF is 65 watts and a comparable T5 is only 54 watts. So are 2 65 watt CF's the the same as 2 54 watt T5's?

The answer to this question has so many variables that it cannot be condensed into just a few sentences but I'll try. For starters, a typical 65w compact fluorescent lamp produces approximately 4,000 lumens. A typical 54w T5 HO fluorescent lamp produces 5,000 lumens. So right there you can see that you're starting out with 25% more lumens from the 54w T5 HO lamp vs. the 65w CF lamp.

Next you would need to measure the actual light that reaches the aquarium at various depths. This depends on several factors, not the least of which is the quality of the reflectors and the amount of light that is actually reflected downwards and not redirected, as you already pointed out.

In measuring the effectiveness of any lighting in this hobby, we typically measure the amount of Photosynthetically Active Radiation (PAR) incident on a given area and the spectral distribution of that light, expressed as Photosynthetically Usable Radiation (PUR). I have seen such measurements for various metal halide lamps but I don't recall seeing them for compact fluorescents and T5 HO fluorescents.

I really don't have to look up the comparison numbers, assuming they're online somewhere, because I don't consider a 65w CF lamp to be anywhere close to a 54w T5 HO lamp because of the inherent differences in the way they are made, as you already pointed out. I do recall seeing a comparison of light output between identical T5 HO fluorescent lamps with different reflectors and that comparison was VERY impressive. An individual reflector for each T5 HO lamp makes a very big different in the total output.



P.S. -- Don't forget that wattage is merely a measure of power consumption. One lamp may be three times as good as another lamp of the same wattage as shown by tests of metal halide lamps. For example, in one of Sanjay Joshi's tests he measured three times as much PAR from a 175w Ushio 10,000K lamp compared to a 175w Venture 5,500K lamp.

Obviously PAR measurements will vary depending on the distance of the light source from the meter but Sanjay tests all of his lamps from a standard distance. Unfortunately, I don't believe Sanjay has tested any lamps other than metal halides.