New lighting - how much brighter?

Carissa

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Jun 8, 2007
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I am upgrading my 30g tank from 2 - 24" T12's (ODNO 2X) to a Coralife T5 dual light strip (18W per bulb 30"). How much more light is this likely to give me, if any? The reason I am upgrading is because something weird happened with the old fixture and it melted part of the plastic when a bulb failed, so I don't trust it anymore. Also because it will cost me almost as much to replace the bulbs with the proper T8s as to get a new fixture.
 

Carissa

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Jun 8, 2007
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I just found this spreadsheet I forgot I had that does a calculation of relative 'wpg' based on the type of bulbs and size of the tank. I can't find where I downloaded this originally on the web but someone did this up to provide a sort of more accurate comparison of wpg between different tanks and types of lighting. Obviously it's not exact. When I plug in the numbers I get about 1 wpg with my current setup, compared to 1.2 with my new setup. So maybe about 20% more lighting than I have now. Which would be just fine with me. Does that sound approximately correct?

Another issue that will be addressed is that my bulbs now are only 24" so the sides of the tank are very poorly lit, this will be addressed with a 30" light strip which will distribute lighting more evenly.
 

VaughnH

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T5NO lights aren't nearly as bright as T5HO lights, because of the reflectors normally used on the HO lights, plus that the bulbs are just overdriven to a higher brightness. I don't know what the ratio is though.
 

Carissa

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Jun 8, 2007
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Yeah, I have a T5 HO on my sw tank and it's insanely bright for just having two tubes. I'm sure the NO are not like that. I found this comparison chart:

Lighting - Pets & Ponds

It compares the lux of various light fixtures. The Coralife NO T5 is fairly low especially compared with the Hagen HO T5 which is what I have on my other tank. The wattage is double but the lux is actually triple. I would have bought the Hagen single tube fixture if they had it in 30" size but they don't.
 

ccLansman

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Jan 22, 2008
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anyone give me a heads up as to why the lux on the current fixture is much lower then the orbit at the same exact watt levels? Im no genoius but if you pump the same amount of power into the same bubls the only difference could be the reflector and is the orbit reflector that much better? If not the orbit ballast must be pumping more into the bulbs. I hate to say it but its interesting to also note that the more it costs the "better the specs." Makes me want to say they want you to drop more $$$ on their site. And the actual readings are bogus...
 

Philosophos

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The fact that this site measures in lux kind of makes me want to facepalm. Lux measures perceived light by the human eye, not total radiation and not PAR. What stimulates the cones in your eyes is not the same as what keeps plants growing.

Compare RGB color matching functions:
http://upload.wikimedia.org/wikipedia/commons/8/8f/CIE_1931_XYZ_Color_Matching_Functions.svg

To PAR:
http://upload.wikimedia.org/wikipedia/en/7/72/Par_action_spectrum.gif

In the matter of it being posted on the same site selling you the lights, I would definitely say that there's a conflict of interest. Would you buy a car based strictly on literature provided by the salesman? I would rather go to a more neutral, credible source than try to play around spotting bias.

-Philosophos
 

Carissa

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ccLansman;35499 said:
anyone give me a heads up as to why the lux on the current fixture is much lower then the orbit at the same exact watt levels? Im no genoius but if you pump the same amount of power into the same bubls the only difference could be the reflector and is the orbit reflector that much better? If not the orbit ballast must be pumping more into the bulbs. I hate to say it but its interesting to also note that the more it costs the "better the specs." Makes me want to say they want you to drop more $$$ on their site. And the actual readings are bogus...

Not to defend them, I have no idea if the readings are correct or not, but this doesn't stand up to logic. The Hagen T5 HO is nearly $100 less than the Coralife 4x65 watt and the bulb replacement cost is nearly one third the cost of the other unit, yet they are saying it has nearly 2000 more lux. Seems counterproductive if their idea is making money off of people by skewing their numbers. It also seems reasonable that on average, you will pay more money for something that provides more light.

For the Current and Coralife fixture comparison, it could be reflectors, it could be ballasts, it could also be different types of bulbs too. As mentioned, lux measures what the human eye sees, and different bulbs produce radiation in different areas of the spectrum, some of which is not visible light but may still be useful. The Current fixture is about $50 more expensive than the Coralife, you would think there would probably be some reason for that.

I agree that getting information from people who are selling you equipment is not the most unbiased method and PAR would be better. If anyone has this information (comparisons of various lighting fixtures on the market) I would be very interested in seeing it. I take everything with a grain of salt, especially if it's coming from someone trying to sell me something. But without a better source of information or the resources to do my own testing, I'm stuck with it, such as it stands.
 

Philosophos

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Honestly? It's hard to make a bad choice with custom lighting. Buy what looks good. Having a large spike on the spectrum at just under 400nm isn't the best thing in the world, but people still do fine with it. I'm of the mind that stimulating carotenoids by avoiding anything with a 475-525nm deficiency can help with red in plants. That's just my observation though; nothing conclusive.

At 3wpg CF, some of my plants are almost growing too fast. I've favored sunpaq and coralife because of availability. Both work, even 50/50 actinic blue can grow plants.

-Philosophos
 

Tom Barr

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Jan 23, 2005
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Carissa;35508 said:
I agree that getting information from people who are selling you equipment is not the most unbiased method and PAR would be better. But without a better source of information or the resources to do my own testing, I'm stuck with it, such as it stands.

You sound like the politicians(us) and the banks(sales folks):)
I really don;t trust some marketing BS, I need more to convince me.


Regards,
Tom Barr
 

Carissa

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Jun 8, 2007
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I didn't say I was convinced. Just that I have no other sources of evidence available so I have to make a judgment call on my own. Also, the future of the country or my own financial state is not at stake here. :) So the consequences of misinformation in this case are not that hard for me to deal with even if it is the case.
 

SuperColey1

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Feb 17, 2007
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Buy a decent T5HO and then buy some quality tubes for it. Don't assume that a good light unit also has a good light!!!

They should be using the same tubes to test units and vice versa use the same unit to test different tubes.

That way they can say 'X'brand setup is best but 'Y'brand tube is better. They are taking 'X'brand unit out of the box and then using X brand tubes in it.

This doesn't prove much at all :) Add to that the lux being of not much worth and it makes it a 'we do more advanced testing than most' marketing hype :)

At the end of the day T5HO beats the pants off PC/PL lighting. T5 standard does too. This is all assuming good positioning and good reflectors of course ;)

I think I'll stick to my LEDs :D

AC