Which T5 should I get

[Canadian]

Originally Posted by Myka

You're comparing grapes to raisins. 8 bulbs x how many watts? 54w? That is 432 w (quick math I hope that's right haha). You can't compare 432w of T5 to 250w of halide! That's not a fair comparison. PLUS, you have to use the same Kelvin bulbs in order for it to be accurate. According to Steve (Stir Crazy) actinic bulbs put out a false high PAR reading as well, so if you have actinics in your 8 bulb fixture you're not getting an accurate reading.

In order to compare T5 to MH you need to make sure all the variables are equal...this is where a lot of people fail, and come up with misleading numbers which they now think is the be all end all.

If you're going to calculate the T5 as if it's going on a 4 foot tank (54W) then you also need to be reasonable about the application of the MH - no one is going to try to realistically light a 4 foot tank with a single 250W MH. So consider that the above example is likely 2 x 250W MH in a real-world application (although that's purely speculation on my part as I wasn't the one making the claim - but it's certainly a reasonable consideration).

Secondly, very few people actually recommend running T5HO actinic lamps. A typical application would include lamps measured some where around 450nm but generally not pure "actinic" 420nm. And as an example even a 250W AB 10,000K on an M80 ballast has its largest peak at 420nm (actinic) so I suppose it's producing false high PAR readings?

[i have crabs]

Originally Posted by Canadian

If you're going to calculate the T5 as if it's going on a 4 foot tank (54W) then you also need to be reasonable about the application of the MH - no one is going to try to realistically light a 4 foot tank with a single 250W MH. So consider that the above example is likely 2 x 250W MH in a real-world application (although that's purely speculation on my part as I wasn't the one making the claim - but it's certainly a reasonable consideration).

Secondly, very few people actually recommend running T5HO actinic lamps. A typical application would include lamps measured some where around 450nm but generally not pure "actinic" 420nm. And as an example even a 250W AB 10,000K on an M80 ballast has its largest peak at 420nm (actinic) so I suppose it's producing false high PAR readings?

ive tested a few different setups, the 4 foot tanks i tested were under 2 250w's for comparison, the tek i have tested equall to a 400w even, the 400w was a tar ballast and not so nice reflector though, personally i hate how every t5 thread goes this way every time, im just stating facts that ive tested with my own par meter for my own knowledge, if anyone wants to listen great if not fine too my corals are doing great in a 27" deep tank with the light way higher than it needs to be so in my opinion tek lights work great, i havnt yet tested any higher end 48" t5 lights that would make a fair comparison so im still a bit skeptical on how much better the light output is on them, personally i think its mostly name and features like cooling and dimming that make the over double the price

[Canadian]

Originally Posted by i have crabs

ive tested a few different setups, the 4 foot tanks i tested were under 2 250w's for comparison, the tek i have tested equall to a 400w even, the 400w was a tar ballast and not so nice reflector though, personally i hate how every t5 thread goes this way every time, im just stating facts that ive tested with my own par meter for my own knowledge, if anyone wants to listen great if not fine too my corals are doing great in a 27" deep tank with the light way higher than it needs to be so in my opinion tek lights work great, i havnt yet tested any higher end 48" t5 lights that would make a fair comparison so im still a bit skeptical on how much better the light output is on them, personally i think its mostly name and features like cooling and dimming that make the over double the price

I'm not sure why this was directed at me as I was defending your comparison of 8x54W to a 250W while deducing that the tested 250W set up was actually 2 x 250W while Myka erroneously assumed the comparison was to a single 250W.

With respect to the "double the price" comment I agree. I don't believe that the prices charged for the higher end fixtures are necessarily justified as being purely a consequence of quality or features. In most cases fixtures fetch those prices based on brand IMO. But it's also true that there are few "half the price" fixtures that incorporate active cooling, splash guards, quality individual parabolic reflectors, and good ballasts/components.

[lastlight]

For some visual appeal is its own performance stat I suppose. The higher end fixtures have the much nicer extruded aluminum shells which I think are well worth the extra money. If you're going to put it in a canopy go retrofit in my opinion.

[Canadian]

Originally Posted by lastlight

For some visual appeal is its own performance stat I suppose. The higher end fixtures have the much nicer extruded aluminum shells which I think are well worth the extra money. If you're going to put it in a canopy go retrofit in my opinion.

Respek! Aesthetics fit into that category that's hard to quantify but definitely commands higher prices. I've told you before in previous conversations that I think the white Sfiligoi Stealth fixtures are easily the sexiest fixtures on the market right now. And at one point in time I had actually paid for one but quickly found out that the smaller Mini Stealth fixtures don't employ active cooling and had to cancel the order.

[lastlight]

Much easier to quantify once your wife throws the spank-down on the appearance of every other fixture out there lol. She's not the designer type but I've worn off on her over the years. I was truly in love the day she told me I wasn't allowed to retrofit. She liked the Giesemann Spectra as well.

[lorenz0]

aww T5 threads make my day. But the info is right, active cooling does play a big role with t5's. Tek lights are still good and most people have a issue dishing out the cash for the higher end fixture. myself i am planning on replacing my tek with either a Aquactinics Constellation or a ATI powermodule in the near future. But don't hate on the tek's, they aren't all that bad. Like i have stated before there are people out there with amazing tanks with current usa t5 fixtures with amazing results.

[banditpowdercoat]

Originally Posted by Canadian

With respect to the "double the price" comment I agree. I don't believe that the prices charged for the higher end fixtures are necessarily justified as being purely a consequence of quality or features. In most cases fixtures fetch those prices based on brand IMO. But it's also true that there are few "half the price" fixtures that incorporate active cooling, splash guards, quality individual parabolic reflectors, and good ballasts/components.

It is one thing that I am allready sic of in this hobby. The gross overpricing of equiptment once you put "Aquarium grade" on it. Me, being an electrician, Know the costs of alot of things. And I hate it that the same item is cheaper if its for Commercial installations, rather than Industrial. but in reality, its the same darn thing....

Cost DOES NOT allways mean quality

[i have crabs]

no, not aimed at anyone, personally i like the good stuff and have often payed more for a similar product just cause its cooler(to someone i guess) i like to have a nice looking fixture even if its hidden in a canopy,, like my $600 reddragon return pump im quite shure is just a pump with a fluvalfx5 impeller and i nice housing ohwell its cooler shure ill pay $500 more than a mag pump. not quite shure what part of my brain turns off when i look at aquarium equipment

[Myka]

Originally Posted by Canadian

If you're going to calculate the T5 as if it's going on a 4 foot tank (54W) then you also need to be reasonable about the application of the MH - no one is going to try to realistically light a 4 foot tank with a single 250W MH. So consider that the above example is likely 2 x 250W MH in a real-world application (although that's purely speculation on my part as I wasn't the one making the claim - but it's certainly a reasonable consideration).

Secondly, very few people actually recommend running T5HO actinic lamps. A typical application would include lamps measured some where around 450nm but generally not pure "actinic" 420nm. And as an example even a 250W AB 10,000K on an M80 ballast has its largest peak at 420nm (actinic) so I suppose it's producing false high PAR readings?

Actually, LOTS of people run 420 nm bulbs...but the tendency is leaning away from it, yes.

You're still not comparing fairly. A 54w T5 is more intense than a 39w T5 no matter how long it (obviously) is. Just like having a 400w MH is more intense than a 250w. This is taking the same Kelvin bulbs into consideration though...for arguments' sake here. If you want to take the coverage of the bulbs, then you have to break down that 48" T5, and cover a 24x24" area with 4x54w T5 bulbs (breaking them in half to be 24x24"). Now, compare 4x54w T5 bulbs to a 250w MH. OR you have to compare 2x250w MH to 8x54w T5 to get the same coverage per 24x24" space as typical T5 spacing is 3". Comparing 4x54w T5 to 2x250w MH is hardly a fair comparison.

OR, you could try comparing it that way, but you would have a very complicated mathematical equation to figure out how many watts per square inch and PAR over the total useful area, and you would have to determine what PAR is considered usable, and wow that would be quite a chore.

Plus...it REALLY depends on what T5 and MH bulbs you choose, but even moreso for MH. You can get more PAR out of a 175w Iwasaki SE bulb run on an electronic ballast than half the 250w SE bulbs run off an electronic ballast. The amount of wattage actually used... Oh, and then you have reflectors to talk about too...

My point?? It is very difficult to give an ACCURATE judgement between MH and T5 by the average hobbyist. That's better left to the professionals. It's just better to realize that there are applications where T5s will be better than MH and there are applications where MH will be better than T5.