Lux Meter, Par Meter, whats the difference??

[LostInTheDark]

I'm not all that interested in measuring how much light is at each spot in my tank. I would like to track how much light my 8x80 t5s are giving off. I would rather use a meter to tell me the lights need changing, rather then just by looking at the calendar. Can a $15 lux meter from Amazon tell me that or do I need a $300 par meter? Would these be the right tools I'm looking for or is there an alternative?

 

[ash9965]

i hear there are good phone apps for free that can do it

 

[saltyfilmfolks]

I'm not all that interested in measuring how much light is at each spot in my tank. I would like to track how much light my 8x80 t5s are giving off. I would rather use a meter to tell me the lights need changing, rather then just by looking at the calendar. Can a $15 lux meter from Amazon tell me that or do I need a $300 par meter? Would these be the right tools I'm looking for or is there an alternative?

Yup exactly right. the hand held is best yes. The Milwaukee w underwater if your ever curious is $65 to $75 and lux to par conversions are easy to find on advanced aquarist googles.

Also search LUX here and youll find some good recent conversations.

 

[alton]

A Lux or Foot candle meter can tell you how much light you have, a PAR meter tells you how much quality light you have to grow plants and corals

 

[ash9965]

does anyone know the best android app for this ?

 

[saltyfilmfolks]

does anyone know the best android app for this ?

galactica for iphone
lux light meter by crunchy byte box for android. best of 14 I tested.

 

[Sabellafella]

I'm not all that interested in measuring how much light is at each spot in my tank. I would like to track how much light my 8x80 t5s are giving off. I would rather use a meter to tell me the lights need changing, rather then just by looking at the calendar. Can a $15 lux meter from Amazon tell me that or do I need a $300 par meter? Would these be the right tools I'm looking for or is there an alternative?

Im doing a rightup on an ati fixture with bulbs life/temp and water clarity as soon as my bulbs get changed next month. If you want i can pm you what i have now Nd your going to have to just take me word on it. I drop my fixture down 2 inches after 2 months for loss in par, i run a dimmable so my bulbs comeout every 8-10 months. After 2 months you wont really see a loss in par but the first 2 drops about 5-10%. Alot of people like lux meters but the only time i would ever use one is if im using leds. Par tells you the overal usuable light.

 

[saltyfilmfolks]

Im doing a rightup on an ati fixture with bulbs life/temp and water clarity as soon as my bulbs get changed next month. If you want i can pm you what i have now Nd your going to have to just take me word on it. I drop my fixture down 2 inches after 2 months for loss in par, i run a dimmable so my bulbs comeout every 8-10 months. After 2 months you wont really see a loss in par but the first 2 drops about 5-10%. Alot of people like lux meters but the only time i would ever use one is if im using leds. Par tells you the overal usuable light.

are you tracking intensity too? that would also be a good point of data. cheap too.

 

[LostInTheDark]

That is exactly the info I'm looking for. I know bulb life depends on temperature(room and fixture) and length of use. I'm just looking for something to give me a magic number that tells me its time to change your bulbs.

 

[saltyfilmfolks]

That is exactly the info I'm looking for. I know bulb life depends on temperature(room and fixture) and length of use. I'm just looking for something to give me a magic number that tells me its time to change your bulbs.

there are actually many charts out there. time for the hard googling.
here's a giessman
https://www.reef2reef.com/threads/g...son-pics-par-and-a-whole-mess-of-data.200357/

 

[Blue Lip]

Lux meter for light intensities. Par meter for spectrum of light. That is what I think.

 

[Sabellafella]

are you tracking intensity too? that would also be a good point of data. cheap too.

Dude im dumbfounded with a lux meter man its prob the most simple piece of equipment to use. I see people doing sweet conversions and all these tricks with them but i just dont understand it, especially with t5s. With leds you can see shadowed zones.

 

[Sabellafella]

are you tracking intensity too? that would also be a good point of data. cheap too.

Whats crazy is without the use of (in my case carbon not uv) can effect par up to 30% or more. Theres also a 10%loss in par if your bulbs arent under 41°

 

[LostInTheDark]

Whats crazy is without the use of (in my case carbon not uv) can effect par up to 30% or more. Theres also a 10%loss in par if your bulbs arent under 41°

I know the dimmables have a variable speed fan but mine do not. It has a switch to increase the voltage to speed up the fans but is manual. Where exactly do you take this reading as the exit temp of the air from the fixture is higher then 41.

 

[Sabellafella]

I know the dimmables have a variable speed fan but mine do not. It has a switch to increase the voltage to speed up the fans but is manual. Where exactly do you take this reading as the exit temp of the air from the fixture is higher then 41.

Mine runs from 37-42 and the fans work on auto. , i manually put the fans on high till it got down to around 36 (during the peak of the lighting) and there was over a 10% difference in par, its also funny that on the sandbed i hit 300 par right 30 inches down from were the fans are from the fixture, and a foot down to the left of it i get about 180

 

[saltyfilmfolks]

Dude im dumbfounded with a lux meter man its prob the most simple piece of equipment to use. I see people doing sweet conversions and all these tricks with them but i just dont understand it, especially with t5s. With leds you can see shadowed zones.

scientifically, I wouldn't do any thing more than measure lux intensity at the top of the water or at a set distance from the tube. Anything else is already being observed in par readings.

if you measured par at the same set distance as the LUX intensity it would be a more easily observable phenomenon.

Ie @ 8in lux drop is 0% but par drop was 30% over X days or weeks.
And each would become only one more line of comparable data.

 

[alton]

That is exactly the info I'm looking for. I know bulb life depends on temperature(room and fixture) and length of use. I'm just looking for something to give me a magic number that tells me its time to change your bulbs.

I used a foot candle meter for years for this, check the lamps when new, and then when they dropped 10% I would replace them

 

[ash9965]

galactica for iphone
lux light meter by crunchy byte box for android. best of 14 I tested.

cant find this one in play store ?

 

[ash9965]

I found one by PheeDev ?

 

[JBNY]

They measure the light differently. LUX measures how the eye sees light, green and yellow are given more weight than red and blue.

PAR measure the light evenly across the visible light spectrum.

The LUX converters work only as well as the light that you are measuring. If the light has a big spike in the blue and nothing in the green, the conversion will be not as accurate if the light being measured was uniform across the whole spectrum.