par or lux meter?

[reef_guru]

would you use a par or lux meter for corals? and why?

[Diver_1298]

Par.
Lux is a value of illumination, and while this is helpful it does not necessarily reflect the amount useful light (spectrum) that the zooxanthellae in corals need and or use.

Jim

[reef_guru]

i would think both are needed

[Jason McKenzie]

I alway thought there was no such thing as a PAR meter. It was a combination of a LUX meter and colour spectral analysis. Then an equation to determine PAR.
Am I wrong?
J

[Diver_1298]

Most commercial light bulbs from large manufacturers have the lux rating on the side of the box or you can get the information from their website. A Par value on the other hand is next to impossible to get from a manufacturer as they do not see the value in supplying this information.

Jim

[Diver_1298]

Advanced Aquarist's Online Magazine - Product Review: A Comparison of Two Quantum Meters - Li-Cor v. Apogee

Multi-Sensor Quantum Light Meter
Quantum sensors measure light energy at the specific wavelengths plants actually use for photosynthesis. Gather spatial average PAR readings to measure how much light reaches your plant.

Quantum PAR Light Measurement Instruments from Spectrum Technologies, Inc.

Originally Posted by Jason McKenzie

I alway thought there was no such thing as a PAR meter. It was a combination of a LUX meter and colour spectral analysis. Then an equation to determine PAR.
Am I wrong?
J

[glassbox-design]

Par meters do exist, apogee makes some that are often used for our hobby. see this link on a comparison of two popular models. [edit, Diver already posted it ]

Lux meters can be useful in determining when to replace your bulbs.

[Tangster]

Par meters do exist and we use and have one at the shop But PAR is simple a acynonem for Photosynthesizing Active radiation or something like that Its just a complicate way to say that the lighting that the corals or plants need to turn light into food . And LUX meters also exist But a LUX meter can not detect blue and Yellow Light that well I think ? But the best part is the bulb experts have done all the boring work to get a good mixture or gases metals and phosphorous so all we have to do is pick the one we like the best (:

The reason we have the meter is when you have as many bulbs as we run in house and for clients you have to know for sure when the shift off in K values.. Although the rule of thumb is 9 to 12 months LOL not me I find all I ever ran to burn closer to 20 months.. with little shift. And I'll add the German Meters we have cost the boss some big bucks ..

[reef_guru]

Advanced Aquarist Feature Article - February 2002

[reef_guru]

jason and diver, this might be better:
Apogee Instruments: QUANTUM METERS