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Pl, Fl, Mh, T5...


Matt06
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I remember some guru(Tanzy?) says FL offers the best lumen per watt. Which correspond with the article :D However, the report fail to look into the intensity aspect :erm::pinch: (am i correct, jus briefly glance thru the article :P )

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abalone,

When you say T8, do you have examples like pictures of how it look like?

The T number refers to the diameter of the tube in inches, as measuared in 1/8 of an inch.

So a T8 is exactly 1 inch in diameter (BTW, this is the standard FL tube used in homes). A T5 is 5/8 of an inch in diameter.

An yes. a FL tube can never compare to MH in terms of intensity. It doesn't have the power to punch light through to the bottom of a 2 foot tank. It is a diffuse source of light spread though 24+ inchces of light source, as opposed to light coming from a 1 inch pinpoint source in MH.

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Comparison between type of light is not straight forward as it is dependent on a lot of factors.

1. Livestock or corals that you're keeping

2. Depth of tank

3. Replacement cycle

4. operating costs

5. Space for the lights over your tank

Between using a 400W MH lamp and 10 units of 40w T5s, firstly electrical consumption is similar but here's the differences:

YOu get more coverage area out of the T5 but less intensity in any area...

You can only adequately light up the first few inches of your tank with the T5 but the MH can still light light it up a few times more intensely at a depth 8-10 times your T5 can support....

Replacement cycle - T5 ~ 6-7 months at most MH 10-12 months now look at your cost..... say T5 at $40/pc x 10 =$400 MH at $200 x 1 = $200 and at approximately 1.7 times the cycle that you need to change your T5 . Summary for every 1 MH bulb you replace you have changed approximately 15 units of T5 lamps... T5 in the long run is a more expensive option in the long run. To match the area covered by the light you can use two 250w MH and still your T5 cannot match the intensity it delivers at 24 inches depth.

Heat = Heat given off is still the same.. 400 watts of MH is still 400 watts of T5 . T5 just spreads it out over a large area while MH is concentrated in a small area. Of course the incidental IR rays from MH can penetrate the water deeeper due to the intensity while T5 can penetrate to an inch or so only

So which one is better? MH if you're keeping light loving SPS and T5 can do the job on the rest except certain LPS but then only on shallow tanks. If you keep deep tank 24 inches or deeper MH is still the way to go for most LPS. Only softies can go for less intense light.

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Comparison between type of light is not straight forward as it is dependent on a lot of factors.

1. Livestock or corals that you're keeping

2. Depth of tank

3. Replacement cycle

4. operating costs

5. Space for the lights over your tank

Between using a 400W MH lamp and 10 units of 40w T5s, firstly electrical consumption is similar but here's the differences:

YOu get more coverage area out of the T5 but less intensity in any area...

You can only adequately light up the first few inches of your tank with the T5 but the MH can still light light it up a few times more intensely at a depth 8-10 times your T5 can support....

Replacement cycle - T5 ~ 6-7 months at most MH 10-12 months now look at your cost..... say T5 at $40/pc x 10 =$400 MH at $200 x 1 = $200 and at approximately 1.7 times the cycle that you need to change your T5 . Summary for every 1 MH bulb you replace you have changed approximately 15 units of T5 lamps... T5 in the long run is a more expensive option in the long run. To match the area covered by the light you can use two 250w MH and still your T5 cannot match the intensity it delivers at 24 inches depth.

Heat = Heat given off is still the same.. 400 watts of MH is still 400 watts of T5 . T5 just spreads it out over a large area while MH is concentrated in a small area. Of course the incidental IR rays from MH can penetrate the water deeeper due to the intensity while T5 can penetrate to an inch or so only

So which one is better? MH if you're keeping light loving SPS and T5 can do the job on the rest except certain LPS but then only on shallow tanks. If you keep deep tank 24 inches or deeper MH is still the way to go for most LPS. Only softies can go for less intense light.

:bow::bow::bow::bow:

very well put across ...

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robe,

a very well, simple & understandable statement.

However, not to dispute your other points, I would like to point out isn't MH bulbs are best to replace every nine months or so? I believe some hard core sps lover do so.

Whereas for T5, which I am currently using, it is rather new in the industry. I personally received an email to state that T5 need to be replaced every 18months.

But usually I will give some discount on such statement. Hence I put it the replacement period for T5 at ~12mths

Nevertheless, I fully understand your other points & agree totally with them.

Those are the reasons why I am going into MH too :angel:

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robe,

a very well, simple & understandable statement.

However, not to dispute your other points, I would like to point out isn't MH bulbs are best to replace every nine months or so? I believe some hard core sps lover do so.

Whereas for T5, which I am currently using, it is rather new in the industry. I personally received an email to state that T5 need to be replaced every 18months.

But usually I will give some discount on such statement. Hence I put it the replacement period for T5 at ~12mths

Nevertheless, I fully understand your other points & agree totally with them.

Those are the reasons why I am going into MH too :angel:

Let's get some data :eyeblur::eyeblur::eyeblur:

EA11_3.gif

T5 lifespan not that great ??? At the worst lifespan of 10,000 hrs, if you on it for 8 hrs daily, it will last 3.425 years. But 10,000hrs is based on 3 hrs, not 8. So it should last longer. :lol::lol::lol:

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I think the thing here everyone has forgotten is the intensity of the output of the bulb over time.

Everyone knows that PLs are good but after the 5th month or so, the intensity of the bulb has dropped a lot. I am not too sure about T5s, assuming like all FL bulbs, there will be loss of intensity too.

As someone who has moved from FL to PL to 150w MH to 400w MH, I can tell you that there is a lot of difference and will never look back to having anything less than a MH bulb for a 2ft deep tank.

But that's just me! ;) I am an advocator of MHs now. :D

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3 years? That's running the tube into the ground.

Light intensity is crucial. Maximum bulb life is not a concern at all for the reefer, it's more of useable bulb life. For a Radium MH, that will be about 6 months before the corals turn brown and start receding.

post-36-1093875548.jpg

Warning: Heavy handed moderator in operation. Threads and post are liable to be deleted or moved without prior notification.

Moderator's prerogative will be enforced.

Any grievances or complains should be addressed to The Administrator.

http://www.sgreefclub.com/forum/uploads/post-36-1073276974.gif post-36-1073276974.gif

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I think the thing here everyone has forgotten is the intensity of the output of the bulb over time.

Everyone knows that PLs are good but after the 5th month or so, the intensity of the bulb has dropped a lot. I am not too sure about T5s, assuming like all FL bulbs, there will be loss of intensity too.

As someone who has moved from FL to PL to 150w MH to 400w MH, I can tell you that there is a lot of difference and will never look back to having anything less than a MH bulb for a 2ft deep tank.

But that's just me! ;) I am an advocator of MHs now. :D

More data then :P:P:P

EA11_4.gif

Conclusion ? You probably got the wrong tube. get T8 or T5 with instant start and/or rare earth. Dont get halophosphor. Dont get high out. Then, after 10000hrs, you still have 90% or slightly less of the original rated lumens!!! :yeah::yeah::yeah:

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Are there 10000K and Actinic rare earth phosphor lamps? Never heard of them. It depends on the ballast they are driven on too.

post-36-1093875548.jpg

Warning: Heavy handed moderator in operation. Threads and post are liable to be deleted or moved without prior notification.

Moderator's prerogative will be enforced.

Any grievances or complains should be addressed to The Administrator.

http://www.sgreefclub.com/forum/uploads/post-36-1073276974.gif post-36-1073276974.gif

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Are there 10000K and Actinic rare earth phosphor lamps? Never heard of them. It depends on the ballast they are driven on too.

You are right. Electronic ballast is the only choice.

".................

Table 1: Recommended characteristics for electronic ballasts

The following guidelines apply to general lighting applications. A qualified lighting designer should be consulted for specific installations.

Recommendation

Power factor Minimum 0.95

Current crest factor Maximum 1.7

Total harmonic distortion Maximum 20%

Frequency Minimum 20kHz

Transient protection Category A, IEEE 587

Sound rating "A"

Flicker factor Maximum 5%

Ballast factor Minimum 0.88, unless exceptionally low light is required. Maximum 1.20

History Two years of production and documented performance, or satisfactory performance in an on-site pilot project.

Warranty Minimum 3 years, including a $10 per unit labor allowance for failed ballasts.

..............."

This is getting too tough right? Time to sleep......... :snore::snore::snore::snore:

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Wow, that is lots of information, anyway, my friends in the tank really suffer as those at the sand bed are not able to get enough light supply as my tank is 2ft deep. That is why I am thinking of switching from PL direct to MH...

Do consider T5 but I think it is really not much of a different.

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Abalone,

All this info is very interesting, but it begs the main question that is on most reefer's mind.

The main purpose of lighting is to provide sufficient LIGHT to the tank inhabitants.

That is, does the FL tube have the necessary power to provide 250+ µE/m2 of light to the bottom of a 2 foot tank necessary to sustain clams and other light demanding organisms.

As Robe already pointed out in another thread, empirical data clearly shows that T8, VHO or PL (and probably T5) clearly falls short of that mark at the bottom of a 2 foot tank (and not even at the top of a tank).

http://www.advancedaquarist.com/issues/aug...003/feature.htm

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Abalone,

All this info is very interesting, but it begs the main question that is on most reefer's mind.

The main purpose of lighting is to provide sufficient LIGHT to the tank inhabitants.

That is, does the FL tube have the necessary power to provide 250+ µE/m2 of light to the bottom of a 2 foot tank necessary to sustain clams and other light demanding organisms.

As Robe already pointed out in another thread, empirical data clearly shows that T8, VHO or PL (and probably T5) clearly falls short of that mark at the bottom of a 2 foot tank (and not even at the top of a tank).

http://www.advancedaquarist.com/issues/aug...003/feature.htm

If you are talking about Photosynthetically Active Radiation. Some fluorescent wins MH hands down. :ooh::ooh::ooh:

faq0017_0800.pdf

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