Lux meter- am I doing it right?

[ksc]

What brand t5 fixture do you have?

 

[DracoKat]

I just took another reading of the top, it says 706 now

 

[DracoKat]

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=23758

4 bulb, 48".

I mentioned the bulbs above- ATI bulbs

 

[saltyfilmfolks]

If I remember correctly, about 6-7". A generic t5 fixture will put out about 4-500 at that height and 100 on the sand in that tank.

yea it should be more in the neigborhood of 35000-40000 lux on that and an ati fixture should be slightly more.
that being said. 35000 devide by 45(d riddle) is 777 par, pretty in line with your numbers.

My ati coral plus was 40000 lux at 6- 8 in.

@DracoKat Im not sure whats up with the meter. it all seems high.

 

[DracoKat]

I have it on the 5000 setting.. do I have it on the wrong setting? I have no idea how to work this thing, lol

 

[DracoKat]

I have it on the 5000 setting.. do I have it on the wrong setting? I have no idea how to work this thing, lol

 

[DracoKat]

I have it on the 50000 setting.. do I have it on the wrong setting? I have no idea how to work this thing, lol

 

[saltyfilmfolks]

Funny, I just triple posed another thread just now too.

 

[ksc]

My guess (I've owned a par meter for about 8 years and tested over 100 tanks) is you are getting about 6-700 par at the waters surface and 150-200 at the bottom. This would be in the center of the fixture and those numbers would fade quickly on the sides with your fixture that close to the water.

 

[DracoKat]

I thought my internet was wonky.. glad it wasn't me. oops.

@ksc - You know better than I do! I did test on the side, not in the center. I should do center. based on your guess, would be be OK for a clam and/or a nem?

 

[saltyfilmfolks]

My guess (I've owned a par meter for about 8 years and tested over 100 tanks) is you are getting about 6-700 par at the waters surface and 150-200 at the bottom. This would be in the center of the fixture and those numbers would fade quickly on the sides with your fixture that close to the water.

yup

I thought my internet was wonky.. glad it wasn't me. oops.

@ksc - You know better than I do! I did test on the side, not in the center. I should do center. based on your guess, would be be OK for a clam and/or a nem?

yup

 

[DracoKat]

@saltyfilmfolks love the straight forward answers, lol. Thank you!

 

[ksc]

The nem would find a spot where it's getting enough light. A clam would be ok at least halfway up in the center of the fixture. With only 4 bulbs the light will fade off fast in the front and back.

 

[saltyfilmfolks]

@saltyfilmfolks love the straight forward answers, lol. Thank you!

:)

@ksc Its nice to have a par meter guy in the house.;)

I have a squamosa in about the same amount may a bit more light its middle, but bottom actually. but led w lenses. Was halide. so a bit different falloff but both are close.

 

[ksc]

:)

@ksc Its nice to have a par meter guy in the house.;)

I have a squamosa in about the same amount may a bit more light its middle, but bottom actually. but led w lenses. Was halide. so a bit different falloff but both are close.

I had a squamosa on the sand under my halides. It grew very fast at 250 par, so much so that I moved it into the center under the brace. My BIL has a deresa in his 75gal tank under generic t5's, doesn't grow much but has been looking good for 6 years. He keeps it about half way up.

 

[saltyfilmfolks]

I had a squamosa on the sand under my halides. It grew very fast at 250 par, so much so that I moved it into the center under the brace. My BIL has a deresa in his 75gal tank under generic t5's, doesn't grow much but has been looking good for 6 years. He keeps it about half way up.

yea once i got the halides dialed in mine grew fine. It got hot I went led, and im still bringing up the intensity slowly.
Still seems happy as a clam:p

I will say though. working with many folks like you and using Dana riddle's numbers on lux conversion to par. Its dang close. its a bit of a trick w led's but....

still not sure whats up with Dracocats meter.:confused: your doing it right as far as i can tell but the reading has got to be wrong. If you put your hand over the sensor does it read zero?

 

[ksc]

You can use the Clear Sky Calculator on apogees site to calibrate a par meter. Not sure if it would work with a lux meter.

http://www.apogeeinstruments.com/when-to-recalibrate-clear-sky-calculator/

 

[DracoKat]

@saltyfilmfolks

I did cover the sensor and it read 0. I put the sensor in different locations under the light and the reading was dramaic

on the side, it reads 525/550
between middle and side: 825/950
exact center: 950-ish

 

[DracoKat]

meter is about 3 inches from light fixture.. water is an inch or so below it

 

[saltyfilmfolks]

meter is about 3 inches from light fixture.. water is an inch or so below it

yea if its that close maybe??still sems a bit higg. but i looked and I thought that meter maxed out at readings of 50,000. looking


http://www.abcgeluid.eu/Handleidingen/ABC.LX1010B_Luxmeter.pdf

yea you should not be able to get a reading of 950 x 100:eek::confused::confused:
how weird

950x100 is about the brightness of the sun. Maybe take it outside?