magnetic1 January 16, 2010 January 16, 2010 Im thinking about replacing my (3) 250W Metal Halide over my 125G (6ft) tank with a single pendant on a light track. Will one pendant running back and forth for 8 hours be enough lighting? It takes 20 min to go 6 feet, so every hour it goes back and forth 3 times. If it is enough, this would be cutting some of my electric bill and lower the heat in summer, which in turn would also lower my chiller use. I figure I'd save about $20-25 per month on electric bill by ditching 500W worth of lighting, not including chiller use. What are your thoughts? http://www.hydrofarm.com/pb_detail.php?itemid=3212
Origami January 17, 2010 January 17, 2010 My gut feel is that if you put fewer photons into the water, you get less photosynthesis. Meaning, you really can't cheat it this way - less light is less light. Any way you look at it, you're putting less light into the aquarium. One benefit, though, of a track system is that you can get more even lighting across the tank this way - fewer shadows, etc. - which can benefit corals that might otherwise find themselves mounted in areas of shadow.
chucelli January 17, 2010 January 17, 2010 I think it's certainly worth a try.. I seem to recall something in a biology paper that mentioned intensity was more important than the duration, as long as it was past a certain (x) amount. (x) is what I don't remember exactly... but I know that corals can reach photosaturation in ≈4 hours. So for example, it you were to blast them with intense light for 4 hours straight and then darkness for the next 20 hours, they would still be able to generate enough sugars through photosynthesis. -Robert
lhcorals January 17, 2010 January 17, 2010 I for one do not think 1 light would be enough. 2 lights might because you would still have light spilling to the sides giving you more coverage. Hope that makes since.
Nate January 17, 2010 January 17, 2010 (edited) I think it would work. I have seen some Sunlight Supply Light Rail Kits and they are pretty sweet. Edited January 17, 2010 by Nate
Coral Hind January 17, 2010 January 17, 2010 Visually, I would not think that one light would look good at all. Too much darkness on the sides of a bright light.
Nate January 17, 2010 January 17, 2010 Visually, I would not think that one light would look good at all. Too much darkness on the sides of a bright light. Definitely have to agree with ya.
chucelli January 17, 2010 January 17, 2010 I think it's pretty cool to have some shadows... but that's just me. Perhaps you could use 1 400w bulb on a track. -R
lhcorals January 17, 2010 January 17, 2010 I think it's pretty cool to have some shadows... but that's just me. Perhaps you could use 1 400w bulb on a track.-R You would still only get 2 to 3' of coverage from side to side with a 400 watt MH. If the light is all the way to the left side of the tank, the right side is going to be pretty dark. That is why i recommended 2 lights. I would try to space them 2' apart starting from the end of the tank. In other words measure from the end of each side of the tank 2' and mount you lights at that point on the light rail. That way you have spillage from side to side.
hypertech January 18, 2010 January 18, 2010 One of the LFS here in MN did that moving 1 400W (I think) over 4 feet of a shallow frag tank. They had a hard time keeping the corals colored over time and ended up shutting it down. If I were going to do that, I would take the suggestion to drop to 2 bulbs and have them move back and forth. Then you have good coverage for high light stuff in the middle all the time and can keep less demanding things on the sides.
Jon Lazar January 18, 2010 January 18, 2010 You might try putting the MH on the moving track, but add a few T5s that run the length of the tank and provide constant illumination.
Coral Hind January 18, 2010 January 18, 2010 You never mentioned what type of corals you had or the photo period of your current setup. Sure one light in a set up as you mentioned would work fine for lower light demanding corals. If you want high light demanding SPS, then it wouldn't work so well.
ebman74 January 19, 2010 January 19, 2010 It will work...see links below for video where a coral frag farmer is using this method. I beleive it is in part two. http://www.lafishguys.com/57-%20CoralFragFramer-01.htm http://www.lafishguys.com/57-%20CoralFragFramer-02.htm Greg You never mentioned what type of corals you had or the photo period of your current setup. Sure one light in a set up as you mentioned would work fine for lower light demanding corals. If you want high light demanding SPS, then it wouldn't work so well.
paul b January 19, 2010 January 19, 2010 I think you have too much light anyway. I have a 6' tank with two 150 watt MH lights over it. I really should have three of them but it would still be half of what you have. I also don't have to run a chiller.
Coral Hind January 19, 2010 January 19, 2010 I think you have too much light anyway. I have a 6' tank with two 150 watt MH lights over it.I really should have three of them but it would still be half of what you have. I also don't have to run a chiller. Is this an SPS dominated tank? What types of corals do you have?
paul b January 19, 2010 January 19, 2010 (edited) No It is LPS and clams. I only have two sps but the tank at one time was predominately SPS. I still feel that you have plenty of light and can easily get by with 3 150 watt or 175 watt MH lights. Your tank is also not very deep, My 6' tank also could use one more light only because the ends are a little darker so I don't have any corals on the sides. Just my opinion of course. Edited January 19, 2010 by paul b
ctenophore January 19, 2010 January 19, 2010 I use light movers in my greenhouse over my sps tub and am happy with it's performance. 1x250w will be enough for you. I have 2x400w over a 6'x10' tank (travels the 10' length). I agree that if you use the T5 as continuous light, you will get a better visual effect. DFS uses light movers too, as do many other coral farm operations. If the store in MN couldn't keep sps happy with a 400w moving over just 4' of tank, then it was something other than the light. Try agramover.com for a well made motor, it uses standard unistrut for a track which you can buy at home depot. I use aluminum unistrut from mcmaster.com though, so it doesn't rust.
Origami January 19, 2010 January 19, 2010 I'm curious, Justin. Does your reflector cover the 6' width of the tank, then, while the motor covers the 10' length? What PAR are you getting at the coral depth? Also, how long are you running the light per day? I'm interested in finding out how many umol/m-sec (and ultimately, per day) are being delivered to the inhabitants by your lighting setup since it's light that drives photosynthesis.
magnetic1 January 19, 2010 Author January 19, 2010 I use light movers in my greenhouse over my sps tub and am happy with it's performance. 1x250w will be enough for you. I have 2x400w over a 6'x10' tank (travels the 10' length). I agree that if you use the T5 as continuous light, you will get a better visual effect. DFS uses light movers too, as do many other coral farm operations. If the store in MN couldn't keep sps happy with a 400w moving over just 4' of tank, then it was something other than the light. Try agramover.com for a well made motor, it uses standard unistrut for a track which you can buy at home depot. I use aluminum unistrut from mcmaster.com though, so it doesn't rust. Thanks Justin, I might try it. Right now Im going SPS, but I have LPS in tank. The tank has (4) 36" T5s used for actinic lighting in the canopy. If I did this, the track would have to be attached onto the canopy and raised up. The ceiling is kinda high where the tank is so I dont know about mounting to the ceiling and having it hang down so far. Actually, I think the end result in all this will be my wife telling me Ive made her kitchen look messy resulting in me having to revert back to my old setup
ctenophore January 19, 2010 January 19, 2010 I'm curious, Justin. Does your reflector cover the 6' width of the tank, then, while the motor covers the 10' length? What PAR are you getting at the coral depth? Also, how long are you running the light per day? I'm interested in finding out how many umol/m-sec (and ultimately, per day) are being delivered to the inhabitants by your lighting setup since it's light that drives photosynthesis. The reflectors are lumenarc 3. They are 22" wide so roughly 4' of the 6' is covered by reflector. PAR is about 200 umol on a completely cloudy day. I am running these lights 13 hrs/day since sunlight is so variable and weak right now. On a sunny winter day, PAR is near 500-600 from the sun only. Summer day with no shade, par is near 1200. I am trying to aim for 500-600 max, with a 200 baseline. This seems to be working for about 2/3 of my sps, which have reasonably good color (some have excellent color). The other 1/3 are brown, mostly corals that would normally be purple. Most every colony is growing at some level, some quite fast, others slowly.
Coral Hind January 19, 2010 January 19, 2010 If you go with this proposed system the photo-period will have to be increased from where it is currently. This is needed to make up for the amount of time the corals will be in the shade while the light is at the other side of the tank. Factoring in the additional photo-period expense, expense to change out the systems, an additional mechanical system that can break while on vacation, and wifes approval. I would just stick with what you have. Just my two cents.
ctenophore January 19, 2010 January 19, 2010 If you go with this proposed system the photo-period will have to be increased from where it is currently. This is needed to make up for the amount of time the corals will be in the shade while the light is at the other side of the tank. If you add a pair of T5 at each end (4x36 total) I doubt you would have to run the MH more than 10-12h/day. Factoring in the additional photo-period expense, expense to change out the systems, an additional mechanical system that can break while on vacation, and wifes approval. I would just stick with what you have. Just my two cents. Wife approval and aesthetic rating are quite important. I think the mover is a pretty solid piece of equipment though, basically just a low RPM AC gearmotor. Even if it stuck in one place, I doubt it would do much damage. I think it is a worthwhile experiment and that the whole lightmover concept is underrated in the hobby. You could do what I did with the streams attached to the lightmover; make a plastic brace that hangs down along the back edge of the tank to hold a nanostream or similar. If you hide it properly you could get the benefit of wavemaking from the lightmover and possibly get rid of some powerheads in your display. Not having seen your setup I don't know if this is possible but worth looking into. I think it would look best with a full canopy to hide the mover.
ctenophore January 19, 2010 January 19, 2010 Justin, Are you going to try this on your display tank? I have an idea in the works to combine both a mover and LED spotlights.
magnetic1 January 19, 2010 Author January 19, 2010 If you add a pair of T5 at each end (4x36 total) I doubt you would have to run the MH more than 10-12h/day. Wife approval and aesthetic rating are quite important. I think the mover is a pretty solid piece of equipment though, basically just a low RPM AC gearmotor. Even if it stuck in one place, I doubt it would do much damage. I think it is a worthwhile experiment and that the whole lightmover concept is underrated in the hobby. You could do what I did with the streams attached to the lightmover; make a plastic brace that hangs down along the back edge of the tank to hold a nanostream or similar. If you hide it properly you could get the benefit of wavemaking from the lightmover and possibly get rid of some powerheads in your display. Not having seen your setup I don't know if this is possible but worth looking into. I think it would look best with a full canopy to hide the mover. i guess I could always build another canopy. Just needs to be taller. Not sure the powerhead idea would work sine the center braces of the tank would get in the way?
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