Frag Propagation lighting ????

[roland jacques]

I'm planing a propagation system The Tank size will be 96" x 30" wide the depth will be 20" but have "tables" inside the tank to bring the corals to just below the surface. efficiency is big for me. so i was plaining on using Three or Four 250 or 175 watt metal halides.

I'm up in the air about which reflectors to use. My goal is 300-400 PAR at 10" of depth. So I'm basically looking for a reflector that will give a wide pattern 24" or 30" square 10" below the water. The lights can be as high off the tank as needed, any opinions welcome.

 

[james s_]

The LumenBrights with 175 W Iwasaki 15k would be my choice If I was using MH. Low wattage and good Par.

 

[roland jacques]

James, That is exactly the combo i was looking at first, but i am a little unsure.
At first it seemed the lummenbrights where concentrating the light too tightly, but now im not sure what to make of the data. Are people getting wider pattens with lummenbright by just raising them up and not loosing to much light? I was trying to sort all that out on RC but im still not sure .

And if i had to raise them very high to get a wide patern do i need to step up to 250 watts

any other opinion on this

 

[cameron]

Personally, I run with one MH light with a great reflector on a rail. That is effecient lighting wise.

 

[james s_]

Cameron;118755 wrote: Personally, I run with one MH light with a great reflector on a rail. That is effecient lighting wise.

There ya go. That would be great on a Prop system. Im not sure one would suffice on such a long tank though.You could get by with 2-175 MH instead of 3. Using one of those 3.5 Light rails.

 

[cameron]

Yeah that is a long way for one light, but two would certainly work.

 

[james s_]

Roland Jacques;118751 wrote: James, That is exactly the combo i was looking at first, but i am a little unsure.
At first it seemed the lummenbrights where concentrating the light too tightly, but now im not sure what to make of the data. Are people getting wider pattens with lummenbright by just raising them up and not loosing to much light? I was trying to sort all that out on RC but im still not sure .

And if i had to raise them very high to get a wide patern do i need to step up to 250 watts

any other opinion on this

Well the Lumen Brights are supposed to be good at directing the light but you do lose some "Spread" with them. You could regain some of that spread but lose some Par with the Lumenarc's. But if your only looking for 300 par at the surface then just about any reflector would work would it not?

 

[cameron]

This is odd, but you could do one hanging 36" or 48" T5 fixture on a rail especially since you don't need high PAR or good PAR low in the tank.

 

[cameron]

46bfinga;118764 wrote: Well the Lumen Brights are supposed to be good at directing the light but you do lose some "Spread" with them. You could regain some of that spread but lose some Par with the Lumenarc's. But if your only looking for 300 par at the surface then just about any reflector would work would it not?

Inexpensive spider reflectors may be the best choice.

 

[roland jacques]

I have a brand new mover from way back that been just setting in my garage, I'm missing the track.

I do want to maximize growth. (subscribing to Dana Riddle's not too much light concept) So with one light on a rail, how much growth would i be giving up??? compared to 3 lights

 

[roland jacques]

46bfinga;118764 wrote: But if your only looking for 300 par at the surface then just about any reflector would work would it not?

Im looking for 300-400 at the depth of 10". Over the wide 24" area

 

[cameron]

Lets say you run one light and it lights up a coral 30% full and another 30% half as the light moves over. Typical lighting runs 8-12 hours lets settle on 10. If you run an additional 3-4 hours you are pretty much giving the coral the same lighting as if you ran lighting over it all day. While the pattern isn't the same as the sun, it is time wise closer. As the sun rises and sets along with cloud cover, I have to imagine that those hours are giving very little PAR due to the angle of the sun and/or the density of the clouds.

The cool part is if you don't like the results just add another MH onto the rail.

 

[roland jacques]

Cameron;118775 wrote: Lets say you run one light and it lights up a coral 30% full and another 30% half as the light moves over. Typical lighting runs 8-12 hours lets settle on 10. If you run an additional 3-4 hours you are pretty much giving the coral the same lighting as if you ran lighting over it all day. While the pattern isn't the same as the sun, it is time wise closer. As the sun rises and sets along with cloud cover, I have to imagine that those hours are giving very little PAR due to the angle of the sun and/or the density of the clouds.

The cool part is if you don't like the results just add another MH onto the rail.

Yeah, Wow, cool. Cameron, I think I love you. :blush:

 

[cameron]

I just want to hear the results of the setup. I hope to setup a frag tank when we move houses and always wondered how well those rail systems work.

 

[roland jacques]

Cameron;118768 wrote: Inexpensive spider reflectors may be the best choice.

I'm cheap but Reflectors is not the place i want skimp. The differance in PAR between a Spider VS a Lumenarc or Lumenbright... is huge. (not sure, but i think it is about 80-100% more light) They more than pay for themselve. It like free light or like a higher wattage bulb with no extra power consumption.

 

[cameron]

True enough. The nice part about improved reflectors is you can always lower them closer or raise them from the water to adjust PAR. If you know what your PAR max is (assuming you have one), cheaper ones might work but I am with you.

 

[cameron]

Yeah I let that one go... Roland is too cool to be messing with.

 

[roland jacques]

The max Par may get confusing with the moving light. So im thinking 30%- 50% more PAR may be in order.

This photo was very helpful to me, comparing lumenbright to lumenarc III

I wonder if the lumenarcs were older reflectors maybe dirty or something. the differance seemed a bit much.

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[james s_]

I saw that too. It seemed a bit far fetched to me.

 

[roland jacques]

I'm thinking that distance could be part of the reason for the big jump. If they did this comparision again maybe at 14" above the water, we may see some much closer numbers. 21" off the water is a long way non focused reflector. so yeah 14" and 21" would give a better picture of whats going on with the comparision.