Lights and Lux

[geoffrey]

Hi All,

Like to know among all the available types of light, PL, FL, MH, Mercury Vapour and etc, which has the highest lux/watt?

[geoffrey]

Hi All,

Like to know among all the available types of light, PL, FL, MH, Mercury Vapour and etc, which has the highest lux/watt?

[geoffrey]

Hi All,

Like to know among all the available types of light, PL, FL, MH, Mercury Vapour and etc, which has the highest lux/watt?

[geoffrey]

Hi All,

Like to know among all the available types of light, PL, FL, MH, Mercury Vapour and etc, which has the highest lux/watt?

[Simon]

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On 10/31/2002 9:31:37 AM

Hi All,

Like to know among all the available types of light, PL, FL, MH, Mercury Vapour and etc, which has the highest lux/watt?
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think its difficult to measure the amount of light received (lux), anyone wanna bag up a luxmeter and do a test?

in terms of brightness/intensity, MH and MV is yr best choice (in this hobby)
when selecting lights of yr planted tank, the depth must be determine as certain types of tube cant or weakens thru deeper tanks... I find that FL shld not be used in tanks above 2ft (inclusive of gravel)

[sherchoo]

In terms of efficiency, MH has the highest lux per watt. Next would be MV. Followed by PL and the FL.

So far in commercial lighting, High Pressure Sodium is the most efficient. But this light is very very yellow.

[geoffrey]

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On 10/31/2002 4:06:01 PM

In terms of efficiency, MH has the highest lux per watt. Next would be MV. Followed by PL and the FL.

So far in commercial lighting, High Pressure Sodium is the most efficient. But this light is very very yellow.
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Hi Sherchoo,

Does that mean that if I have now 4 x 36W PL totalling 144W for my tank, and if I switch to MH, I will need less than 144W in order for my plants to flourish?

[sherchoo]

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On 10/31/2002 5:29:54 PM

Hi Sherchoo,

Does that mean that if I have now 4 x 36W PL totalling 144W for my tank, and if I switch to MH, I will need less than 144W in order for my plants to flourish?
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Geoffrey,

Yes, but how much less I wouldn't know.

[geoffrey]

Thanks, Sherchoo.

[geoffrey]

Sherchoo,

Forget to ask these, will MH deteriorate over time? Like PL and FL.
Anyone attempted to DIY or modify there existing FL or PL to hold MH tubes? Any idea what hardwares are needed?

[vinz]

FLs/PLs have different light radiation pattern from MH. PLs and FLs have a linear coverage, MH has a spot effect. The brightest will be directly under the MH.

[sherchoo]

MHs are said to last for a period of 2 years while FL/PL would last for 6 months.

[vinz]

Ehhh... FLs last 6 mths, PLs last 12.

[Simon]

but they usually lose their effectiveness b4 then... therefore, always wise to change yr tubes b4 they blow or when u realise yr plant growth has slowed down..

[vinz]

Simon, those are the suggested time for replacement. I.e. they'll last longer, but after those times, the intensity will drop drastically.

[Simon]

yup, just informing those who only change their light tubes only after they burn out... but I'm guilty of that too.. the FL hasnt been change for more than 2yrs... kekekeee... but i rotate the tubes with another 4 tubes.. every once in a while

[tawauboy]

for fl tubes you can notice a big drop in intensity after 6 months.
can try to recycle by reusing it for room lighting if yoou home is using fl fittings.

[Simon]

jus an area of discussion, anyone seen or use FL tubes with 'rechargeable' specs?

[tawauboy]

you mean 'rechargable' as in increasing the intensity back like new?
if so, i don't think it is possible.
it has to do with the electrode at both end of the fl.
as you use it the metal will evaporate thus producing less electrons.
less electrons will excite less of the phosphor coating inside the tube so less light emitted.