MH efficiency loss vs T5

[VJV]

Hi. I now this is a simple question with a very technical and difficult reply but the reason I ask is the following: we have seen in videos from BRS that 8 bulb T5 fixtures from ATI produce a ton of PAR, more than is actually needed. They tested it using 24w bulb fixtures.

Now the question is, if instead of an 8 bulb we would use a hybrid 4 bulb T5 plus a 150w MH, which would produce the higher par...?

Understand there are reflectors and other bits at play here, but from a pure wattage perspective we would be “replacing” 4 24w T5 bulbs (or 96w) by a 150w MH, so a 50% increase in wattage.

However, from what I have read and understand a lot of the watts in MH are transformed into heat rather than actual lighting (surely the gurus will walk all over this statements but anyway) so at the end of the day, theoretically at least, how many watts of MH would I need to replace 96 w of T5.

Would love to hear your thoughts and please, no LED comparison as really I want to keep it between MH and T5.

 

[jackson6745]

Since you're talking about a single 150w halide I would assume the fixture is 24". 150w halides absolutely suck. Low par, low spread, the t5's from an ATI will provide more par and coverage. 150's don't put out a major amount of heat but it will definitely add more heat that your typical LED cluster or T5 tube. It's just not worth the effort because the performance will be less, you might see some shimmer come through.... that's about it. To utilize a halide and make it not such an energy hog, you must utilize the spread. This means larger reflectors, large bulbs (single ended), higher wattage so you can get adequate par lifting fixture/bulb higher, and a tank that is deep enough to utilize the spread.

Not sure about MH light being transferred from heat, but having run radion g4's over my 32x32 cube, and 400w radium + halide, I can tell you that nothing compares to the coverage/visual appeal as the 400w radium. Based on coverage alone a 10 bulb ATI powermodule that I had on there was insane. T5's are awesome but I just get tired of the flat hue from them in a display tank.

 

[VJV]

Thanks! I am actually comparing 8 bulb T5 against 150w MH plus 4 bulb T5 (two on each side). Or in other words, how would the 150w compare to 4 T5s, if this makes sense.

 

[jackson6745]

Thanks! I am actually comparing 8 bulb T5 against 150w MH plus 4 bulb T5 (two on each side). Or in other words, how would the 150w compare to 4 T5s, if this makes sense.

The 8 bulb will give you better coverage and par. The 150w will not make up for 4 t5's in an ATI fixture. You need to step the wattage up to a 250w to make a difference but that won't fit in a slim fixture. I would opt for 2x XR15 pros over the single 150w to replace 4 of the 8 t5's. You'll get better coverage and more penetration with the radions.

 

[jackson6745]

This will work
IMG_1118 by rich colombo, on Flickr

 

[VJV]

The 8 bulb will give you better coverage and par. The 150w will not make up for 4 t5's in an ATI fixture. You need to step the wattage up to a 250w to make a difference but that won't fit in a slim fixture. I would opt for 2x XR15 pros over the single 150w to replace 4 of the 8 t5's. You'll get better coverage and more penetration with the radions.

Thanks. My options are either Giesemann infinity or the ATI. Do not want to consider LEDs. I wanted to keep it more generic so hence the comparison for a generic 24 inch size.

However my tank is a 80”x22”x24” peninsula so I am actually looking for the 72” version of the infinity (3 x 150w MH + 4 x 80w T5) vs a 60” 8 bulb T5, which I currently have.

Front to back it is just 22” so do not need a ton of spread but the 60” 8x80w T5 do not provide adequate coverage lengthwise.

Hence me looking for the 72” Infinity. As long as the three 150w MH would not imply a significant par loss over the 4 80w tubes.

 

[VJV]

This will work
IMG_1118 by rich colombo, on Flickr

[emoji23]

 

[jackson6745]

Understood, however, I would still go for the Spectra and run 250w radiums. The spread will be sufficient enough that you can run T5's only for dawn + dusk. You'll save the energy difference and get better par numbers through the tank + an overall better look. 150w DE are better suited for nano tanks. I'm not a fan of any DE halide really, they are as inefficient as it gets. High par but terrible spread. Also, there is almost no demand for an infinity vs a spectra if you decide to sell.

 

[jackson6745]

Spectra + blue reefbrites 400w radium for reference. I have yet to recreate this light with anything else. G4 pros and t5 combo give me hope though
jan 23 2015 by rich colombo, on Flickr

 

[VJV]

Thanks. I know a lot of LED fans would disagree but to get he kind of uniform coverage I like with Radions or other high end LED fixtures in my 80” tank I would need at least 5, preferably 6 dialed down to about 50-60%. However, 6 Radions would set me back 5400€ vs 1800€ for a 72” Sepctra with Dimmable T5 ballasts (controlled by my Profilux 4). It would take 9 years of bulb replacements to justify the cost.

My concern would be heat, hence looking at the infinity. Tank is sitting in the main living room so I do not want to run a chiller... hence my question on 150w MH vs 96w of T5. Or in this case, 450w of MH vs 320w of T5.

 

[jackson6745]

I understand your dilemma. I currently run a 32x32 cube but I'm upgrading to a larger 72" long reef with a coming move. To go all LED you are right, you will need 5-6 radions for complete coverage no matter what the spec says. Very pricey and that option is out for me as well. I am considering running 3 radion g4 pros on a 72" (mounted length wise) tank with 4 overdrive T5's on an Ice Cap 660 ballast. This is the kind of lighting that you would have to hide in the wall or have a canopy etc.

Out of your considerations I would choose an ATI T5 fixture with added reefbrites. You will not be happy with the 150w halides and the t5's in the Giesemann put out very low par. I get 200par from the t5s at the surface in my spectra, where in an ATI fixture I get 600 par at the surface. Yet another consideration The heat from the 250's really isn't that bad. If ambient room temp is kept 72F or cooler you won't need a chiller. I never used a chiller even with 400w.

 

[mcarroll]

luminous efficiency isnt that far apart on T5 and halide under good circumstances...even at 150 watt. (Lack of 150w Radiums for sale is a problem tho.)

watts are watts when it comes to heat...so think about heat management if heat is important.

What is the idea behind 4xT5+halide again since 8xT5 has too much light?

Why not just look at 6-bulb T5?

( I read the opener but I'm not sure I get it still.)

 

[VJV]

We do not have Reefbrites in Europe so that one is unfortunately out. When you say you get 600 par with the ATI is that with 8 bulbs? Not sure how that would compare to the Spectra given it only has 4 bulbs. And the relationship between par and bulbs is not proportional given more bulbs create a multiplying effect.

I currently have a Giesemann 8x80 Matrixx ii dimmtec and am emerald pleased with it (in fact, I suspect for a 22” wide tank a 6 bulb would probably fine) but my problem here is that it does not adequately cover my 80” tank end to end. If it were a 72” I would not hesitate but for the 80” there is too much unlit real estate.

I can either go with two 39w ATI units (6 or 8 bulb) or the spectra/infinity.

My room does get up to 80F during summer so heat from light can be an issue.

 

[mcarroll]

u run a chiller for summertime heat management, ir something else?

 

[VJV]

Currently I am not using anything for heat management during summertime, except for a slightly reduced max photoperiod. That with the 60” 8bulb T5 unit I currently have.

 

[chipmunkofdoom2]

Thanks. I know a lot of LED fans would disagree but to get he kind of uniform coverage I like with Radions or other high end LED fixtures in my 80” tank I would need at least 5, preferably 6 dialed down to about 50-60%. However, 6 Radions would set me back 5400€ vs 1800€ for a 72” Sepctra with Dimmable T5 ballasts (controlled by my Profilux 4). It would take 9 years of bulb replacements to justify the cost.

Not disagreeing with the coverage or your break even analysis. You are, however, leaving out some costs.

First is power usage. If you use 400w bulbs, the Spectra will use over 1,500W (80w T5s x 4 + 400w MH x 3). If you use 250W bulbs, the usage will be closer to 1,070W. Contrast that to 6x G4 Radeons, which use 190W each, for a total of 1,140w. At 50% intensity, that's probably closer to 500w or 600w. So you're looking at between 50% to 66% power savings using LEDs over MH/T5s, depending upon your bulb choice.

Second is the cost of chilling a tank. I have trouble keeping my tank at 79* in the summer, and that's using LEDs or T5s. I would absolutely need a chiller if I used anything MH, which I don't have. That would be an extra cost. Additionally, my electricity bill would almost certainly go up from the extra heat from the chiller and MH.

I don't mean to disparage T5s or MH. T5s and MH combos are great, and they're still incredibly relevant in the hobby today. If I could choose any lighting at all, I would probably run just MH with no supplemental lighting. At the end of the day, you should use the light you like the most that gives you the results you want. I just think we need to be a bit more sophisticated than just considering fixture costs and bulb replacements when comparing disparate lighting technologies.

 

[mcarroll]

I still feel like I am missing the goal of the conversation.

Are you trying to get more PAR than you have now with 8 bulbs?

The comment you included about the eight bulb fixture putting out more than enough light is throwing me off I think.

 

[VJV]

luminous efficiency isnt that far apart on T5 and halide under good circumstances...even at 150 watt. (Lack of 150w Radiums for sale is a problem tho.)

watts are watts when it comes to heat...so think about heat management if heat is important.

What is the idea behind 4xT5+halide again since 8xT5 has too much light?

Why not just look at 6-bulb T5?

( I read the opener but I'm not sure I get it still.)

Thanks for the input. My intention originally was to hear opinions on how 96w of T5 (4 24w T5 bulbs) compare with 150w of a dE MH.

I wanted to keep it generic and not specific to my tank, as I would extrapolate results for my particular case.

However this quickly shifted to my personal case which is that I want either a single fixture (that needs to look nice because my tank is rimless and a room divider with no canopy) or at worse two, that provide adequate end to end coverage for my 80” tank.

The reason I mentioned the 150w and not the standard 250w MH is because I was wondering if I could get away with less heat and power consumption.

If my current 8x80w (640w total) T5 fixture provides more than enough par (though not end to end coverage) shouldn’t a 72” infinity (4x80w plus 3x150w MH, or 770w total) should be adequate no?

However, apparently for a number of reasons the 150w DE MH bulbs seem to actually provide than what the 4 T5 bulbs they would replace and I should look at the 250Mw Spectra instead.

And I mean “replace in the sense that we are comparing 8x80w T5 vs 4x80w plus 3x150w MH...

I know this may sound a bit convoluted but hopefully now is a bit more clear...?

 

[VJV]

Not disagreeing with the coverage or your break even analysis. You are, however, leaving out some costs.

First is power usage. If you use 400w bulbs, the Spectra will use over 1,500W (80w T5s x 4 + 400w MH x 3). If you use 250W bulbs, the usage will be closer to 1,070W. Contrast that to 6x G4 Radeons, which use 190W each, for a total of 1,140w. At 50% intensity, that's probably closer to 500w or 600w. So you're looking at between 50% to 66% power savings using LEDs over MH/T5s, depending upon your bulb choice.

Second is the cost of chilling a tank. I have trouble keeping my tank at 79* in the summer, and that's using LEDs or T5s. I would absolutely need a chiller if I used anything MH, which I don't have. That would be an extra cost. Additionally, my electricity bill would almost certainly go up from the extra heat from the chiller and MH.

I don't mean to disparage T5s or MH. T5s and MH combos are great, and they're still incredibly relevant in the hobby today. If I could choose any lighting at all, I would probably run just MH with no supplemental lighting. At the end of the day, you should use the light you like the most that gives you the results you want. I just think we need to be a bit more sophisticated than just considering fixture costs and bulb replacements when comparing disparate lighting technologies.

I am not leaving those costs out. I am not going to run a chiller and the electricity consumption cost difference is to me insignificant because:

1) I would likely not run the T5 + MH at the same time, as the 3 250w should provide more than enough par for the 5-6h peak intensity. At 50% that would be 570w on the LEDs vs 750w on the MH.

2) my local electricity costs 0,1648 per KW/h. 6 hours per day times 180w (the extra power consumption of the MH) at that price equals 0,177984 cents per day, or 5,34€ per month.

3) even if I would run the fixture full blast for 6h, the added consumption would be 500w per hour and the extra monthly cost 15€. To me still irrelevant in the wider context and especially compared to the upfront cost of the LEDs

To combat heat during summer I would likely reduce peak number of hours to about 4 and definitely alternate the T5 with the MH to keep heat down, and add some GHL fans controlled by my temp sensor. However, if this would not be enough than MH MH can be a problem as I do not want to install a chiller in my living room.

 

[VJV]

I still feel like I am missing the goal of the conversation.

Are you trying to get more PAR than you have now with 8 bulbs?

The comment you included about the eight bulb fixture putting out more than enough light is throwing me off I think.

I want end to end coverage which I am not getting with the 60” T5 fixture right now [emoji4].

Do not need more PAR as my tank is relatively narrow (22” front to back) and not too deep (24”) and my SPA are growing really well.