T5 + MH PAR - T5 has underwhelming levels, does it matter?

[jd-woodlands]

Just got a PAR meter on my new setup using Geisemann Spectra 48" 4 bulb T5 and 2 x 250MH Radium 20K and was wanting some feedback. Fixture is about 10" off the water.

PAR levels are ~1000 about 7-8" down under water, ~500 bottom of tank midday with T5 and MH running and i'm very happy with that... however running T5 only its ~190 at the same location top, and ~115 or so bottom of tank. Are these levels in line with expected T5 output using ATI Blue+ ?

I'm assuming the mid day PAR values with the MH are providing plenty of growth opportunities and the T5 is just supplemental and theres nothing to worry about.

Any comments would be appreciated.

 

[Joedubyk]

Always depends on bulbs + fixture + size/dimensions of tank. Only 4 bulbs , not sure how high you are hanging them either. I would not worry about not getting enough light lol

 

[blasterman]

T5's need really good reflectors to punch...that's a big reason the industry shifted to T5 vs T8 and T12 even though the bigger tubes have longer lifespans. The smaller diameter of the tube the easier / more economical / more efficient it is to make a reflector.

Although tube fans don't want to admit it the main reason for using hybrid T5's lights is for coverage and unified fill - not PAR monsters. Your T5's might not be the main source of PAR in your tank, but their coverage helps fill in the gaps with SPS and in that respect are worth having.

 

[Acroporaaddict]

1000 par 7-8" underwater? I have the 36" spectra running dual 250w radiums and have noticed my acros have been a little on the pale side even with elevated nutrients. Probably should raise my fixture as my tank is only 12" deep. What ballast are you running the radiums with?

 

[jd-woodlands]

1000 par 7-8" underwater? I have the 36" spectra running dual 250w radiums and have noticed my acros have been a little on the pale side even with elevated nutrients. Probably should raise my fixture as my tank is only 12" deep. What ballast are you running the radiums with?

Running the CoralVue LuXcore Selectable 250 - 400 Watt Digital Electronic Metal Halide Ballast mon the HQI setting.

I was pretty surprised as well at how high the values were, this was measured on an Apogee meter so should be accurate.

 

[jd-woodlands]

Kicking between 945 - 1000 with water flow at the location below with t5 + mh.

 

[jda]

I turn the supplemental lights off when the MH are running... mostly. I just save the energy since the output is not needed anyway - makes the bulbs last longer too.

 

[jporter17]

I turn the supplemental lights off when the MH are running... mostly. I just save the energy since the output is not needed anyway - makes the bulbs last longer too.

This is interesting to me as I have XHOs, T5s and MHs. I may give this a try.

 

[jporter17]

I only run my MHs for 5.5 hours a day between the 2 bulbs with each on a little under 3 hours. T5s run 9 hours daily and XHOs 12 hours with ramp up and down for dawn dusk simulation. I have a 36” fixture over a 48” tank. Your tank looks fantastic by the way. JP

 

[A. grandis]

Just got a PAR meter on my new setup using Geisemann Spectra 48" 4 bulb T5 and 2 x 250MH Radium 20K and was wanting some feedback. Fixture is about 10" off the water.

PAR levels are ~1000 about 7-8" down under water, ~500 bottom of tank midday with T5 and MH running and i'm very happy with that... however running T5 only its ~190 at the same location top, and ~115 or so bottom of tank. Are these levels in line with expected T5 output using ATI Blue+ ?

I'm assuming the mid day PAR values with the MH are providing plenty of growth opportunities and the T5 is just supplemental and theres nothing to worry about.

Any comments would be appreciated.

Unfortunately the Giesemann Spectra don't have those good individual reflectors, nor the amazing cooling system the ATI has for the T5s. The cooling system gives some boost to the efficiency of the T5 bulbs. The Spectra runs very hot and it is basically a halide fixture! The juice comes from the halides and the T5s are just to help with some blue supplementation and to start/end the photoperiod. Yeah, it has 4 T5s but it's not the best, comparing to the ATI system, at all!! The best thing about the Giesemann is the looks of the fixture and the distribution of the light (halides).

 

[oreo54]

Unfortunately the Giesemann Spectra don't have those good individual reflectors, nor the amazing cooling system the ATI has for the T5s.

that's pretty sad for something that expensive..

Basically a bunch of metal and a few ballasts..opp's

Metal halide ballast sold separately.
T5 Bulbs are NOT dimmable.

 

[A. grandis]

The Spectra works great in terms of space and looks, like I've said. The quality of the metal is great and will last! It's an amazing fixture overall and it's worthy of the price because of that, but could be much better if the T5s had outside ballasts and/or cooling system with individual reflectors. I think practically people would prefer how it is though. I guess we can't get everything we want out of every product. There is no other fixture that would substitute the Spectra at this time IMO.
The Cebu is another amazing fixture and if you don't mind the fan and the bulky appearance it will give you great results too! It also doesn't have individual T5 reflectors. Would it be better to have the Cebu in terms of T5s? I'm not sure about the PAR numbers... I would think the Cebu needs to be cleaned often to make sure the fan is doing it's job. Technically speaking the cooler it runs the better for the T5s. Still not the very best, like the ATI system.

 

[jd-woodlands]

Thanks for the comments, definitely got the Spectra due to looks and passive cooling ability. PAR levels with the MH are outstanding so i'm not lacking there. I'm sure the low par with T5's is just fine giving the tank a bit of rest from the mid-day blast of light.

 

[Bpb]

that's pretty sad for something that expensive..

Basically a bunch of metal and a few ballasts..opp's

I've gotta agree there. The price point of the Giesemann hybrid fixtures was absolutely absurd.

Regarding the OP. Because MH bulbs don't need to be cooled, its ok for the fixture to feel like a hot stove, but yes it is bad for the T5 bulbs. Like others mentioned, the T5 are there to fill in some shaded spots for more even coloring, practically speaking. Just supplements. Honestly I would abide by JDA's approach and just run the T5 bulbs when the Mh are off to save their life. It'll keep them cooler. Are all 4 bulbs on the same channel or is it a 2/2 thing

 

[jd-woodlands]

Thanks for the T5 off suggestion, makes sense and will help cool down better.

Updated APEX for T5 ...

Fallback OFF
Set OFF
If Time 08:00 to 20:00 Then ON
If Outlet MH1_2_1 ON Then OFF
IF Outlet MH2_3_2 ON Then OFF
If Tmp > 83.0 Then OFF
Min Time 005:00 Then OFF

 

[alton]

When I ran MH in the summer with heat issues I ran the MH 4 hours a day with led strips at 10 hours a day, winter time I ran the MH at 8. Growth was the same summer or winter. It was like the corals only needed a certain amount of bright light?

 

[oreo54]

When I ran MH in the summer with heat issues I ran the MH 4 hours a day with led strips at 10 hours a day, winter time I ran the MH at 8. Growth was the same summer or winter. It was like the corals only needed a certain amount of bright light?

Look up DLI or daily light integral...

Daily Light Integral, PAR, and Photosaturation Discussion

I'd like to start a discussion based on a few things I've been reading lately regarding optimum daily light integral, PAR and photosaturation in our reef tanks and with the advent of this new lighting forum. For those of you with PAR meters and the ability to continually monitor PAR via an...

www.reef2reef.com

A Different Look at Lighting: Effects of Prolonged Photoperiod, Spectral Quality, and Light Dosage

Some reef aquaria 'experts' have suggested that we understand all we need to know about lighting of reef aquaria. This article will suggest otherwise.

www.advancedaquarist.com

 

[A. grandis]

Thanks for the comments, definitely got the Spectra due to looks and passive cooling ability. PAR levels with the MH are outstanding so i'm not lacking there. I'm sure the low par with T5's is just fine giving the tank a bit of rest from the mid-day blast of light.

Yeah, that's it! There is absolutely no fixture that substitutes the Spectra.
Even if ATI decides to make a similar halide/T5 fixture with their cooling system for the T5s, it probably wouldn't work 100% anyway because the halide's heat would be there also. Spectra rules! No fans, no noise, no maintenance! It will last our life time!
Spectra is a halide fixture with a T5 touch all in one.
Sun in the house! I love it!!!



"Living, moving setion of the reef in your home"

 

[blasterman]

Also, for the record, fluorescent tubes put our more thermal per watt than metal halide and higher wattage levels. The myth of metal halides and heat is just another bad_science myth propagated by reef store clerks making mimimum wage and barely getting their GED. You will raise the ambient temperature of a warehouse faster with 10,000 watts of T5's vs 10,000 watts of halides. T5's can simply hit higher lumen per watt levels at lower wattage levels than halide.

Not sure if this includes induction or cold cathode, but I've never seen those over a reef tank.

Tubes simply distribute that heat over a much larger area than halide bulbs do, so there's the false impression that halides put out more heat.

 

[A. grandis]

Also, for the record, fluorescent tubes put our more thermal per watt than metal halide and higher wattage levels. The myth of metal halides and heat is just another bad_science myth propagated by reef store clerks making mimimum wage and barely getting their GED. You will raise the ambient temperature of a warehouse faster with 10,000 watts of T5's vs 10,000 watts of halides. T5's can simply hit higher lumen per watt levels at lower wattage levels than halide.

Not sure if this includes induction or cold cathode, but I've never seen those over a reef tank.

Tubes simply distribute that heat over a much larger area than halide bulbs do, so there's the false impression that halides put out more heat.

I felt that as soon as I got my Spectra, but I thought the ballast inside of the fixture was the culprit for the extra heat. Maybe the truth relies on both.