250 MH or 400 MH's?????? - Page 3

Maxx · 12-05-2003, 03:43 PM

Quote:

Maxx, I could do that but it would put my PC bulbs 5 1/2" from the open water. Do you think that is a good idea?

Pcs dont get as hot as MH's so temp transfer isnt as big a problem. The only thing I would be worried about would be bulbs breaking from water contact. Can you put a glass or plexi barrier/shield between the PC's and the water?
The amount of light lost on flat reflectors is significant....something like 40%.
Nick

Scooterman · 12-05-2003, 03:49 PM

Troy my VHO's are about that distance off the water, in about a year I just replaced them, had a little salt build-up on the bulbs but other than that no problems.

Maxx · 12-05-2003, 03:59 PM

Just so ya don't think I'm shining you on about the reflectors, here's a product review by Richard Harker explaining why these are effective....http://www.animalnetwork.com/fish2/a...ct/default.asp
Nick

Pro_builder · 12-05-2003, 05:46 PM

Maxx thanks I will change from the flat reflectors.
Are spiders the same as Parabolics?

Maxx · 12-05-2003, 06:07 PM

yes and no...spiders are trademarked....sposed to give better than normal parabolic reflective returns....but parabolics are much better than flats...
Nick

Pro_builder · 12-05-2003, 06:14 PM

ok, I ordered a set of Parabolis for 58.90 from Hello lights.com

Maxx · 12-05-2003, 06:24 PM

should be great....cant wait til the set up is going!
Nick

Pro_builder · 12-05-2003, 10:08 PM

Maxx it should be up and running sometime mid next week.
Thanks again for all you great info and Help!!!

Maxx · 12-06-2003, 01:18 AM

no problem Troy....Glad I could help.
Nick

danny254 · 12-06-2003, 02:48 PM

Hey, I'm really sorry for being late on this, but here's a comparison for 250w SE vs 250 DE

http://www.advancedaquarist.com/issu...03/feature.htm

danny254 · 12-06-2003, 02:58 PM

The DE bulbs do put out more light, but it's a matter of "is it really worth it to deal the the heat for a little more light," If you more concerned about that you can put a mogul base bulb 8 inches from the water and still be safe, if you did that with a DE lamp, there would be a much bigger risk of shattering the safety glass on the fixture.

Maxx · 12-06-2003, 04:24 PM

Danny,
thanks for the input. I had read that article previously, but couldnt remember where it was from. I think an important thing to note is that the author states

Quote:

it is not a fair comparison. First of all, having the lights suspended so high above the tank is not the ideal way to get light into the tank. Most tanks seem to have the lights between 5.5” to 8” off the water. Secondly, the water was fairly turbid, mixed with quite a bit of micro-bubbles from the skimmer. The tank was also bare-bottomed, meaning that these are the deepest readings I have taken, with the sensor a mere 1” off the bottom of the tank.

These bulbs were mounted 9.75 and 15.5 inches respectively off the waters surface. Have you heard of the inverse square law?
It is used in photography and is referenced for lighting subjects...but it applies here too. From petersons photographic library..." The inverse square law is the basis for our understanding of the relationship between distance and illumination level....The law states that the intensity of light decreases as the sqaure of the distance between light source and subjucet increases."
To clarify this the book makes a couple of comparisons..."Let's assume that you have a light source placed one foot from a subject, and you double that distance by moving your subject back two feet from the subject. You're not just cutting the light in half, as you might suspect. You're reducing the light by four times (two squared = four). If you now increase the the subject-to-light-source distance to three feet, you've decreased the illumination level to 1/9th its original intensity, (three squared = nine)."
So keep that in mind when placing lights above your tank and the height you go with. Most people will place their lights any where from 5-8 inches off the surface of their water. If you realize this and then go back and look at the picture of the sunlight supply tank, (mogul/SE ended on right @ 9.75 inches and HQI/DE on left @15.5 inches of height) you'll see that the results are the same when the DE is almost twice as far off the surface of the water. So if we apply the inverse square law here, by placing the DE pendant at the same height as the mogul/SE pendant, the DE would produce almost 4 times the light that the SE/mogul would.
Thats pretty significant to me....

For 4 times the light, I'll find a way to cool the water.
Another thing I noticed about this test was that the author didnt take measurements of the philipines underwater to get a reference to our tanks....just some thoughts,
Nick

Maxx · 12-06-2003, 04:26 PM

BTW,
Travis is one of the Admin's here...he's also a professional photographer...feel free to ask him about the inverse square law.
Nick

Travis · 12-06-2003, 05:31 PM

Nick, you have just stated pretty much everything I know about the inverse square law. LOL

danny254 · 12-06-2003, 05:45 PM

Good point Nick, now I understand more about the intensity of DE compared to SE, but don't you think, since you can put a SE much closer to the water, they would be pretty similar in intesity, directly under the bulb, I understand the spread would not be as good as if it were 12 inches off the water rather than 9, but In cases where you don't need a huge spread, it might be fine.

12-05-2003, 03:49 PM	#32 (permalink)
Scooterman Elegance coral Join Date: Nov 2003 Location: Lafayette, Louisiana Posts: 1,210 View Gallery Karma Komment	Troy my VHO's are about that distance off the water, in about a year I just replaced them, had a little salt build-up on the bulbs but other than that no problems. __________________ Scott Ardoin (Ard-Dwan)

12-05-2003, 03:59 PM	#33 (permalink)
Maxx Manta Ray Join Date: Nov 2003 Location: St Louis Mo Posts: 3,079 View Gallery Karma Komment	Just so ya don't think I'm shining you on about the reflectors, here's a product review by Richard Harker explaining why these are effective....http://www.animalnetwork.com/fish2/a...ct/default.asp Nick __________________ "Chaos, confusion, despair...my work is done here." ...Some guy named Murphy.... A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!" Reef Sanctuary Knowledgebase (Answers to all your questions and then some!)

12-05-2003, 05:46 PM	#34 (permalink)
Pro_builder DIY Moderator Join Date: Nov 2003 Location: Oxford, Iowa Posts: 1,746 View Gallery Karma Komment	Maxx thanks I will change from the flat reflectors. Are spiders the same as Parabolics? __________________ -Troy 180 gallon Reef, 3- 250 XM 15K MH Electronic ballast, 380 watts VHO Actinics, 2- 5 watt LED Moon lights, 100 gal rubbermaid sump, 75 gallon Fuge, ETSS 600 Skimmer, 4700-5400 gph pump for return, Octopus 3000 controller, Iwaki 40 RL skimmer pump, 2- 65w PC 10K fuge lights, 2 55 gallon barrels, Custom light oak stand and hood, misc pumps, extra 600 gallon rated tank size protein skimmer. Purple tang, yellow tang, pacific blue tang, 2 green chromis, 1 Sand sifting star, snails, hermit crabs, 2 mated perculas, pulsing Xenia, Anenome, mushrooms, ricordia, zoanthids, kenya tree 1 1/2" tall, misc other hitchhiker stuff. DIY is my dream... ...well OK the only way I can afford this Addiction!! Just as the light goes on in my head... ... I break the bulb!!

12-05-2003, 06:07 PM	#35 (permalink)
Maxx Manta Ray Join Date: Nov 2003 Location: St Louis Mo Posts: 3,079 View Gallery Karma Komment	yes and no...spiders are trademarked....sposed to give better than normal parabolic reflective returns....but parabolics are much better than flats... Nick __________________ "Chaos, confusion, despair...my work is done here." ...Some guy named Murphy.... A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!" Reef Sanctuary Knowledgebase (Answers to all your questions and then some!)

12-05-2003, 06:14 PM	#36 (permalink)
Pro_builder DIY Moderator Join Date: Nov 2003 Location: Oxford, Iowa Posts: 1,746 View Gallery Karma Komment	ok, I ordered a set of Parabolis for 58.90 from Hello lights.com __________________ -Troy 180 gallon Reef, 3- 250 XM 15K MH Electronic ballast, 380 watts VHO Actinics, 2- 5 watt LED Moon lights, 100 gal rubbermaid sump, 75 gallon Fuge, ETSS 600 Skimmer, 4700-5400 gph pump for return, Octopus 3000 controller, Iwaki 40 RL skimmer pump, 2- 65w PC 10K fuge lights, 2 55 gallon barrels, Custom light oak stand and hood, misc pumps, extra 600 gallon rated tank size protein skimmer. Purple tang, yellow tang, pacific blue tang, 2 green chromis, 1 Sand sifting star, snails, hermit crabs, 2 mated perculas, pulsing Xenia, Anenome, mushrooms, ricordia, zoanthids, kenya tree 1 1/2" tall, misc other hitchhiker stuff. DIY is my dream... ...well OK the only way I can afford this Addiction!! Just as the light goes on in my head... ... I break the bulb!!

12-05-2003, 06:24 PM	#37 (permalink)
Maxx Manta Ray Join Date: Nov 2003 Location: St Louis Mo Posts: 3,079 View Gallery Karma Komment	should be great....cant wait til the set up is going! Nick __________________ "Chaos, confusion, despair...my work is done here." ...Some guy named Murphy.... A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!" Reef Sanctuary Knowledgebase (Answers to all your questions and then some!)

12-05-2003, 10:08 PM	#38 (permalink)
Pro_builder DIY Moderator Join Date: Nov 2003 Location: Oxford, Iowa Posts: 1,746 View Gallery Karma Komment	Maxx it should be up and running sometime mid next week. Thanks again for all you great info and Help!!! __________________ -Troy 180 gallon Reef, 3- 250 XM 15K MH Electronic ballast, 380 watts VHO Actinics, 2- 5 watt LED Moon lights, 100 gal rubbermaid sump, 75 gallon Fuge, ETSS 600 Skimmer, 4700-5400 gph pump for return, Octopus 3000 controller, Iwaki 40 RL skimmer pump, 2- 65w PC 10K fuge lights, 2 55 gallon barrels, Custom light oak stand and hood, misc pumps, extra 600 gallon rated tank size protein skimmer. Purple tang, yellow tang, pacific blue tang, 2 green chromis, 1 Sand sifting star, snails, hermit crabs, 2 mated perculas, pulsing Xenia, Anenome, mushrooms, ricordia, zoanthids, kenya tree 1 1/2" tall, misc other hitchhiker stuff. DIY is my dream... ...well OK the only way I can afford this Addiction!! Just as the light goes on in my head... ... I break the bulb!!

12-06-2003, 01:18 AM	#39 (permalink)
Maxx Manta Ray Join Date: Nov 2003 Location: St Louis Mo Posts: 3,079 View Gallery Karma Komment	no problem Troy....Glad I could help. Nick __________________ "Chaos, confusion, despair...my work is done here." ...Some guy named Murphy.... A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!" Reef Sanctuary Knowledgebase (Answers to all your questions and then some!)

12-06-2003, 02:48 PM	#40 (permalink)
danny254 Midas Blenny Join Date: Nov 2003 Location: Redding, northern CA Posts: 101 View Gallery Karma Komment	Hey, I'm really sorry for being late on this, but here's a comparison for 250w SE vs 250 DE http://www.advancedaquarist.com/issu...03/feature.htm

12-06-2003, 02:58 PM	#41 (permalink)
danny254 Midas Blenny Join Date: Nov 2003 Location: Redding, northern CA Posts: 101 View Gallery Karma Komment	The DE bulbs do put out more light, but it's a matter of "is it really worth it to deal the the heat for a little more light," If you more concerned about that you can put a mogul base bulb 8 inches from the water and still be safe, if you did that with a DE lamp, there would be a much bigger risk of shattering the safety glass on the fixture.

12-06-2003, 04:26 PM	#43 (permalink)
Maxx Manta Ray Join Date: Nov 2003 Location: St Louis Mo Posts: 3,079 View Gallery Karma Komment	BTW, Travis is one of the Admin's here...he's also a professional photographer...feel free to ask him about the inverse square law. Nick __________________ "Chaos, confusion, despair...my work is done here." ...Some guy named Murphy.... A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!" Reef Sanctuary Knowledgebase (Answers to all your questions and then some!)

12-06-2003, 05:31 PM	#44 (permalink)
Travis Smilie Bartender Join Date: Nov 2003 Location: Dallas, TX Posts: 6,657 View Gallery Karma Komment Add yours!	Nick, you have just stated pretty much everything I know about the inverse square law. LOL __________________ Help build the Encyclopedia of ReefKeeping Find over 1400 Reef Aquarium Articles at The Reef Aquarium Index

12-06-2003, 05:45 PM	#45 (permalink)
danny254 Midas Blenny Join Date: Nov 2003 Location: Redding, northern CA Posts: 101 View Gallery Karma Komment	Good point Nick, now I understand more about the intensity of DE compared to SE, but don't you think, since you can put a SE much closer to the water, they would be pretty similar in intesity, directly under the bulb, I understand the spread would not be as good as if it were 12 inches off the water rather than 9, but In cases where you don't need a huge spread, it might be fine.

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