Apogee Quantum Flux Meter

**Shadow** · 24th Mar 2009, 16:41

Does any one heard about Apogee Quantum Flux Meter before? It is suppose to be able to measure Photosynthetic Photon Flux and the sensor can be use under water

. Not cheap though $349 USD (maybe not for some people

). With this you can just ignore watts per gallon thing

.

http://www.apogee-inst.com/quantummeter_techinfo.htm
http://www.apogee-inst.com/manuals/Q...sor_Manual.pdf

**BFG** · 25th Mar 2009, 17:37

I would rather spend the money on something else. If you worry about par level lessening, cool your light tubes and change them every 9 months or up to 1 year.

**Shadow** · 25th Mar 2009, 18:20

More like curious rather than worry.

There alway a discussion on Watt per Gallons rule of thumb. There are many new light technology like T5HO, LED, etc which is more efficient. Thus Watt per gallon may no longer true for those new light technology. Furthermore WPG does not apply for small tank or big tank or odd dimension/shape tank. This device may answer all that, too bad still too expensive.

**BFG** · 25th Mar 2009, 18:55

Here's a link to show how much your T5 may end up after 9 months.

http://archiv.korallenriff.de/Lichttest/T5-1.pdf

**JadeIceGreen** · 25th Mar 2009, 20:47

If one of the LFS could invest in this, they could make LED all the more viable by ensuring that the output is similar to what we are using at the moment. I bet it would be a good investment.

**BFG** · 26th Mar 2009, 21:04

But led bulb is not at peak level. There are newer bulb being produced ever so often and what you've built today might not be at the peak after a few months down the road. Manufacturer might produce even brighter and better led bulb than what is currently available. And if the lfs decide to stock up on a particular brand of led, they might lose out when newer and better stock reach our shores.

**tawauboy** · 26th Mar 2009, 22:05

it is nothing more than a lux meter.
even with this thing, what would be the "guideline/base" level?
fyi, during a cloudless day with the sun overhead, there is > 100,000 lux of light available.

the watt per gallon rule is just a guide. you'll need to adjust to suit what you have in your tank.

**Shadow** · 26th Mar 2009, 23:01

You have to make your own experiment to determine the base level.

This thing should measure all photons from 400 to 700 nm wavelength. What does lux metering measure? Can't seem to find what spectrum does light meter measure

I was studying the plant photosynthetic response when come accross to this device. Only this device give me µmol m-2 s-1 per picture below

Found the following info on the net:
Par meter is weighted to measure par. A lux meter should be weighted to measure LUX (but cheap ones usually aren't). What that means in simple terms is that a blue photon is considered to have more value than a red one and is thus weighted higher according to a scale. The scale is different between the two. There is a conversion factor between the two that is accurate +-5%.

In other word it is totally different than Lux meter. Lux meter does not measure to the photons level but this device does.

**JamesCampbell** · 27th Mar 2009, 00:54

Ya nice gadget but yes quite expensive. If your worryed about light spectrum just keep your bulbs changed every 9 months..... Peace Out

**Shadow** · 27th Mar 2009, 04:55

as I said from the ealier post, more like curious rather than worry. My take for light is giv e them as much as it can fit on top and with EI dossing everything grow nicely.

Somebody probably screaming more light more algae