VHO vs T5 - what's brighter

[Oakie]

What's the diff between a quad T5 and a quad VHO set up. Looking at putting two 4 footers across an 8 foot tank.

[Spindog]

I recently switched from 4x75 (300 watts) VHO's to 4x24 watt (96 watts) T-5's. I think the T-5's are visually every bit as bright as the VHO's were. I posted a comparison a few weeks ago. I'll post the link if I can find it or you could search on my name.

[twkenny]

I have both in my tank...I think it's the reflectors that make the T5's. Add in the increased bulb life, better efficiency and cooler temps and you can't beat them in my opinion.

[d4a2n0k]

4 x 54w T-5's with the proper reflectors will be brighter than 4 x 110w VHO's.

The main thing with T-5s is they must have their own reflectors like the Icecap or Sunlight Supply ones.

[gearhead]

also use an Icecap 660 & overdrive them to 80w each. the T5s are definately brighter w/ more punch than VHO's. i had to move a lot of my softies around & even gave a few away cuz they were starting to bleach out from too much lights.

[Oakie]

How do you go about actually "overdriving" them?

[dhoch]

Oakie,

Using IceCap ballasts will overdrive T5 bulbs.

Here is a link to a thread describing the wattages that will actually be produced: http://archive.reefcentral.com/forum...t&pagenumber=2

I went from 4 x 160 W VHO to 8 x 80 W T5 (overdriven by IC ballasts)... The light difference is huge... In fact many corals had to moved lower in the tank to be happy (a couple of LPS started bleaching). In fact 5 of the 80 W bulbs being overdriven was more light than the 4 x 160 W VHOs in my opinion (I don't have a PAR meter to varify, thats just my eyes talking).

Dave

[STACKER]

Originally posted by Spindog
I recently switched from 4x75 (300 watts) VHO's to 4x24 watt (96 watts) T-5's. I think the T-5's are visually every bit as bright as the VHO's were. I posted a comparison a few weeks ago. I'll post the link if I can find it or you could search on my name.

What wavelength are the lamps in comparison (VHO vs T5)? What are the brand names compared? Are the fixtures and light mountings similar or nearly identical or is one reflected and one not? Was percieved brightness tested using a light meter or was it aside by side by side comparison via human eyes alone?

T5's are less expensive to buy, less expensive to operate, and will effectively generate less heat due to lower output wattage(just logical, yes?) but I'm not convinced that 96 watts of T5 light (in 4 lamps) provides equal usable light wavelength and lumens to 300 watts of VHO in 4-75 w/ lamps. I'd like to see the output chart from tne T-5 and VHO, Mfg.s posted before I agreed with any of the statements above.

I find it interesting that a 204 watt rollback was even contemplated when so many others are clammoring for more and more light in order to simulate the sun. What am I missing here?

I'm not bashing T5's I'm just more interested in factual data and real comparisons of efficiency, cost, and utility. Not conjecture

[gearhead]

do a search for "thegrimreefer". he has done some testing on light readings with a par meter. the T5 actually had better readings than MH lights. BUT MH lights are pinpoint light source T5's are not.

cheack this thread out - http://archive.reefcentral.com/forum...hreadid=561864

all i can tell you is the different reactions that my stuff had - clam spreading out, shrooms & a frogspawn bleaching out. & i have some SPS that is starting to grow (acropora, montis, & a digi).

[PrangeWay]

Depends on the Use.

My theory is,
If it's your main lights T5's are the way to go, if you're just looking for some Actinic supplementation for MH lights go VHO (as the T5 actinics are pretty poor, while VHO's is as good as you get).


PW

[dhoch]

Stacker,

As gearhead suggested do a search on grimreefer and par You should find his par readings for T5 bulbs.

His tests (with single reflectors on T5's) showed that T5 lighting was brighter than MH (250 W bulbs) at shallow depths, but at deeper depths (>18") MH won out, but it would depend totally on Wattages of bulbs and what frequency of light bulbs are producting.

Dave

[STACKER]

I thought the original question was T5 vs VHO. What does MH have to do with this original thought? What is THE defionition brightness (percieved or actual)? Luminescense or wavelength, or both? My argument is not related to MH and not related to unusable light. Specific Kelvin, nM, and UV are produced by a wide spectrum of lamps by their own design, phosphor, and inert gas within. Fish, plants, corals, and inverts donot all necessarily utilize the same levels of either (some overlap, yes). Therefore I can't lend merit to a general statement and and asking for som data so support such a claim. I'm not trying to jerk anyone, just want to know fact.

Being specific in a comparison with regard to apples and oranges (banana's excluded) tends to surround statements in fact rather than "I think it looks brighter" so it is. This holds no water and serves only to promote a line of thought that may or may not be based on fact. There seems to be a growing level of opinion here on RC that is not based on fact or scientific and repeatable evidence.

[dhoch]

I bring in MH because most would consider the answer to the original question posed, iwhich is brighter, between MH and VHO, that MH would hands down be the winner.

I.e. if I say and elephant is bigger than a dog and I say a whale is comparable to an elephant then it is a resonable conclusion that the whale is bigger than the dog (same idea with MH > VHO, T5 ~ (close to) MH => (implies) T5 > VHO)

Standard definitions that I have seen for comparision are PAR (light intensity, brightness or Luminescense) and wavelength (frequencies represented).

My comments on Grimreefers readings are relative to par (light intensity) that's what he measured anyway. And T5s compared favorably to MH (no comparision was done to VHO as far as I know, but I do know that if you search enough you will find VHO to MH comparisions and that MH has more par)

T5s wavelength plots are readily availabe (goto www.reefgeek.com ) and check out the bulbs there plots are available... Also there are threads out and about on this.

Some levels of comparison are visiable to the naked eye. For example many of the "new" headlights are brighter than their older compatriots... I can tell this by looking at them (I don't need a PAR meter to tell me that)... So saying that brighter to the eye is not valid is just well not valid

You started getting into something that was not the original question (brighter light which I took to mean PAR comparisions) which is useable light by fish, plants, corals, etc... This was more than the original question that was asked.

Dave

[dnjan]

The effect of reflectors (as already mentioned) cannot be overlooked. The internal reflectors in URI bulbs are (IMO) not very efficient. A lot of the light that could be produced by the wattage of a URI VHO bulb is not being directed down into the tank. Compare that to a T-5 bulb with a good, external reflector. A very high percentage of the potential light ends up going where it should.

[dhoch]

Don,

Not disagreeing with you, but...

1) the size of VHO bulbs pretty much retstricts the use of this type of reflector

2) I believe the PAR output of a T5 with no reflector still beat the PAR output of a similar wattage VHO.

Dave

[dnjan]

Fully agree that adding proper external reflectors to VHO bulbs would significantly reduce the number of bulbs that can fit in a given space. That is definitely and advantage for thin T-5's.

Not as sure about more PAR from an un-reflected T-5 being greater. Since the light is produced by the phosphors coating the inside of the bulb, that (more PAR from un-reflected T-5) would require significantly more efficient phosphors in the T-5's. If so, why isn't URI using those same phosphors?

Unless, of course, there is a difference in glass thickness which affects the amount of light transmitted ...

[gearhead]

I bring in MH because most would consider the answer to the original question posed, iwhich is brighter, between MH and VHO, that MH would hands down be the winner.

I.e. if I say and elephant is bigger than a dog and I say a whale is comparable to an elephant then it is a resonable conclusion that the whale is bigger than the dog (same idea with MH > VHO, T5 ~ (close to) MH => (implies) T5 > VHO)

uumm...yeah thats what i meant too. i was just using MH lights as something to compare against. My understanding is that the T5s are supposed to be in between VHO's & MH's. Better than VHOs but not quite as good as MH's.

btw, if you really want to get confused on lighting options - do a search for T6 lights.

[dhoch]

Acutally gearhead, my understand from the Par tests is that T5 puts out more par at shallower deptht than MH (doing a watt to watt comparision) but at deeper depths MH wins out (> 18").

Dave

[dnjan]

Can somebody post a link to the T-5 PAR testing work? The limited summaries that have been posted suggest a violation in physics principals, and I would like to read the full details of the testing.

Thanks

[dhoch]

here's a quote from grimreefer measuring the Par's in this thread
http://archive.reefcentral.com/forum...5&pagenumber=2

For those who haven't followed my journey to the dark side I hade a 6x80 watt overdriven T5 on my tank (72"Lx18"Dx23.5"T)and recently swapped them for a 3x150 watt halide with 150 watts of PC actinics. I went from 145 umol's of PAR at the sand, 18" below the surface to just under 100 with the halides.

Here's a link to another thread (I'm not sure where the measurements of lumens/watts came from, but...):

http://archive.reefcentral.com/forum...hreadid=239653

Dallas_Joser:

I finally figured it out.

Halide lumens 85/watt
VHO lumens 50/watt
T5 lumens 75/watt

so 2 x 3ft t5 = 6000 lumens at 80 watts efficiency 75

1 x 6ft VHO = 7500 lumens at 160 watts efficiency 45

or simpler

4 Ft VHO 110 watts at 5300 lumens efficiency 48
4 FT T5 HO 54 watts at 4500 lumens efficiency 83

Simply ~110watts of VHO yields 5300 lumens
and ~110 watts of T5 yields 9000 lumens

Example
1 VHO and internal reflector yield 100 points
then 2 T5 with good reflector yield 350 points
for the same wattage ie almost 4 times as bright
at a slight space cost.

I declare T5 the winner vs VHO but just a hair under Halide

Check the part of the thread just below where I quoted (with the lumens per foot calculation)

THis is of course not PAR but lumen (and supports the "brighter" thing that people notice).

Still looking for PAR information on VHOs.

Dave

[dhoch]

Just an additional note reading furthur in the thread it looks like he did get some Umol measurements (PAR).

Dave

[trippyl]

so what about PC's? Are they chopped liver now?

[STACKER]

Now this data above was what I was interested in. Thanks!

Now, I have a question.

If T-5's are so good why don't more folks use them? Price, real world capability, true efficiency? I have no idea myself so I ask...

[dhoch]

Good question...

I think one is ease of access...

Many places will not ship T5 bulbs (they say the break too easily)... I have to get mine shiped from CA... No one local carries them (yet, but I'm trying to convince my LFS to do so) and quasi local places won't ship em.

The other is education... I had a debate about T5s and brigthness with another reefcentral member (vs MH) and he wouldn't hear or look at the data, just said "Most dealers use MH so it must be better" (that kind of attitude supersedes education).

I think if people relalized the benefits, and truely educated themselves (and didn't belive statements like "MH is the ONLY way to go") there might be more people switching to it.

Now that teklite is mass producting fixtures you are seeing an increase in the use.

Dave

[twkenny]

The shipping thing is kinda funny to me. I've heard that before....but I've ordered from a few places with no problem.