VHO vs. T-5

[WarrenG]

Jeff, unfortunately I have not seen any comparisons of T5 and VHO done by Dana except for the spectral graphs within one of the articles. I did read an off-hand comment attributed to Dana where he said that if he were to choose a system right now (3/07) he would choose VHO's.

I don't have years of experience with SPS, but from what I've seen so far, 500w of VHO is more than enough. Add in Sanjay's comments about light levels needed (I think he's looking more at minimums than optimal), and I don't think it comes down to whether or not VHO's provide enough light, and Dana's articles show that the color spectrum bands (PUR) from VHO's is excellent.

So, other than some people's comments that VHO may provide better colors than T5's (I don't have experience with this) for the choice between T5HO and VHO I think it really comes down to cost to purchase and cost to run.

Well, that plus emotional, subjective rationalizations for the system a person has already chosen. :rollface:

 

[bristlew0rm]

Here is my 2 cents ...

When T-5's starting becoming popular, I really sunk a lot of money into dozens of fixtures. It's been a year and a half and I'm very-very disappointed by how poorly they look even after a few months. When you first fire them up they look awesome, but the color quickly fades. I will never buy anoter T-5 fixture and will always focus my money on MH + VHO actinic supplementation -- there's nothing else like it. I've tried 3 different manufacturer' of T-5 bulbs, and they all perform about the same.

It seems that T-5 bulbs actually dim more quickly than power compact bulbs, but VHO's retain their glow for the full year. It could be because a 4' VHO bulb runs 130 watts, whereas a 4' T-5 bulb runs 54 watts ... I can't say for sure.

 

[bristlew0rm]

By the way, that last comment is directed toward those looking to achieve the best-looking light (which is most important to me). As far as penetration, coral growth, etc -- I've never done a controlled test w/ VHO vs. T5 to measure coral growth (it would be hard since there are so many other factors) ...

VEE-AYCH-OHH ... VEE-AYCH-OHH ... VEE-AYCH-OHH

 

[WarrenG]

Just a little FYI, I bought a light spectrum viewer for $30 and I took photos of the spectrum. After 9-10 months I'll compare a photo of the current spectrum with the original spectrum. Maybe I can use that as a guide about when the lamps should be changed.

A 4' VHO is 110w. I think an overdriven 4' T5 runs near 85w (?). It wouldn't surprise me at all if an overdriven T5 breaks down quicker than when the lamp is run at normal power.

 

[Jacob D]

If you go T5 for supplemental purposes I would not overdrive them, and I would probably use an equal mix of actinic and blue. FWIW I haven't experienced dimming in T5 bulbs, in any case I think it's safe to say that they'll outlast VHO's even if you do overdrive them (which can shorten the bulb life).

The more blue bulbs you add the more you're going to be increasing the PAR. You might even see a short (or long) term lightening of colors due to the added light (same effect as suddenly moving your sps higher under a halide w/o acclimating). Of course once they acclimate you'll most likely get even better growth, the color may or may not be the same as with the VHO's.

I used T5 (only) for years with mixed results. My current tank in progress is using Iwasaki 15k's which I need to supplement. I'm not sure if I'm going to use T5 or VHO yet.... it's a tough decision.... or I might switch to a bulb with more blue and less PAR. So many choices!

 

[Jeff]

<a href=showthread.php?s=&postid=12080844#post12080844 target=_blank>Originally posted</a> by WarrenG
Jeff, unfortunately I have not seen any comparisons of T5 and VHO done by Dana except for the spectral graphs within one of the articles. I did read an off-hand comment attributed to Dana where he said that if he were to choose a system right now (3/07) he would choose VHO's.

I don't have years of experience with SPS, but from what I've seen so far, 500w of VHO is more than enough. Add in Sanjay's comments about light levels needed (I think he's looking more at minimums than optimal), and I don't think it comes down to whether or not VHO's provide enough light, and Dana's articles show that the color spectrum bands (PUR) from VHO's is excellent.

So, other than some people's comments that VHO may provide better colors than T5's (I don't have experience with this) for the choice between T5HO and VHO I think it really comes down to cost to purchase and cost to run.

Well, that plus emotional, subjective rationalizations for the system a person has already chosen. :rollface:

Very very well said

 

[Jeff]

Guys, I agree with your comments regarding T5 bulbs fading over a short period of time. I really am seeing a difference (although I have not tested with a PAR meter). It might just be me but I have 14 T5 bulbs hanging over my tank and I am not "thrilled" rather "pleased" that I can run my 220 reef with around 550 watts of power.

 

[shred5]

One thing that makes t-5 better than vho is the size of the bulb allows for better reflectors. Individual reflectors are the key.

If you are going all fluorescent t-5 is the way to go .. They compair to halides.

If you are buying them to supplement halides I am not so sure. Like I said the individual reflectors are the key and they direct light straight down. They alow for deep penetration of light. I do not think they would mix in well with the halide because t-5 does not spread the light out with idividual reflectors. I am not sure of the par values of vho so a t-5 could be better without individual reflectors still... Not sure though.

Also almost all the vho bulbs that people buy are uri and they now produce almost all their bulbs in t-5 also. Colors are not a problem any more.

Dave