Lux readings

[mcarroll]

I am going to try increasing the intensity slowly. The controller only goes in 5% increments so I'll bump it up by 5% every week or two. With the way it mounts to the biocube (not that well) and the gooseneck being fairly difficult to manipulate I'll leave it as it is physically for now and see if increasing intensity works. It may be that I'll need to also lower it closer to the water as well. Or, I could upgrade to a 360 which should get me some good mileage in increasing intensity.

I realize the app luxmeters are probably not something to live and die by, but honestly I am only looking for approximate values to see if my lighting intensity is reasonable or needs some adjustment. I feel the app at least gives me something to go off of.

Good plan...just need to put a working meter into the equation. And do whatever is easier, for sure. If the mount doesn't allow easy movement, then just work with the fixture's dimming control like you said.

Upgrading to the 360 might make perfect sense, but again I'd have a working meter on hand before forming an actual judgement on that. If you don't mind running the Kessil at 100% and you really can get to 26K lux, then you should be fine.

Unless you want to keep clams. They will definitely require an upgrade....whether you go with two 160's (better for reducing shading) or to a 360.

I've never bothered using a lux meter to measure par.

Since the app's are free, it costs as much to try as to post about. Since you already have a PAR meter, I'm positive folks would be interested in your first-hand observations in comparing the two – especially if you can post your fixture's conversion factor. That still hasn't been done too many times on the forum and every one helps the common knowledge-base.

Just get one compatible with your phone so you're getting sane readings.

 

[ksc]

I don't think my Casio G-Zone has that capability. It does have a compass though....

 

[madweazl]

For giggles I measured it at 65% color (what I typically run at) and 39% intensity (dropped it to 40% a few days ago because the duncan started protesting); 41,800 LUX at ~3.75" (my lights are 4.75" off the water). Distance makes a huge difference in LUX.

 

[mcarroll]

Yup! It's inverse-linear (think that's what you call it) so that reducing distance by half literally results in twice the intensity.

Vis versa too – twice as far from the fixture results in half the intensity at the water surface. (The coverage swings in proportion too....either twice or half the diameter of coverage.)

 

[john.m.cole3]

direct should point at the light. to use reflected put a piece of bright whit paper at the surface and read the paper. its not great but kinda close ish, kinda.

yes you want more than 5 k for sure.


This is the lux meter I have $14 https://www.amazon.com/Docooler-Dig...UTF8&qid=1477324640&sr=8-4&keywords=lux+meter
Maccarol like the one with the hand held attachment $15

If understand the kesil output, you could turn that up to full with no troubles.
Imo on that tank you'd want 25k to 30,000 lux




By knowing what fixture MH T5 and some Led I'm familiar with, Ive been able to estimate Par on on members tanks within 100 par using lux par conversions without even seeing the tank.
And those members OWN PAR METERS.
inside a par meter is a photovoltaic cell. Inside a lux meter there is also one. we had to invent Fc and Lux meters(100 years ago) to make a Par meter.

fwiw a coral plus conversion number is about 38 according to D riddle and apogee as is a 14k mh
a Kessil is around 55 or so, i think higher
a chinese black box is about 63

If you run conversion numbers 40, 50 and 60 you can get pretty dang close, and learn the relationship between intensity and spectrum and getting good par.

if you own a radion and set it to full on all chanells and use the new Apogee designed for Led, set it next to a lux meter, you can make your own lux par conversion.
then also be bummed out because its probably not nearly as good as T5. 5050 Orth a surface reading of 34000 lux in the-55

So how do I convert to par? I have my 48 inch 6 bulb dimmable ati

direct should point at the light. to use reflected put a piece of bright whit paper at the surface and read the paper. its not great but kinda close ish, kinda.

yes you want more than 5 k for sure.


This is the lux meter I have $14 https://www.amazon.com/Docooler-Dig...UTF8&qid=1477324640&sr=8-4&keywords=lux+meter
Maccarol like the one with the hand held attachment $15

If understand the kesil output, you could turn that up to full with no troubles.
Imo on that tank you'd want 25k to 30,000 lux




By knowing what fixture MH T5 and some Led I'm familiar with, Ive been able to estimate Par on on members tanks within 100 par using lux par conversions without even seeing the tank.
And those members OWN PAR METERS.
inside a par meter is a photovoltaic cell. Inside a lux meter there is also one. we had to invent Fc and Lux meters(100 years ago) to make a Par meter.

fwiw a coral plus conversion number is about 38 according to D riddle and apogee as is a 14k mh
a Kessil is around 55 or so, i think higher
a chinese black box is about 63

If you run conversion numbers 40, 50 and 60 you can get pretty dang close, and learn the relationship between intensity and spectrum and getting good par.

if you own a radion and set it to full on all chanells and use the new Apogee designed for Led, set it next to a lux meter, you can make your own lux par conversion.
then also be bummed out because its probably not nearly as good as T5. 50-55

How would you convert a 48 inch 6 bulb dimmable ati fixture with a surface lux reading of 34000?

 

[Breadman03]

Yup! It's inverse-linear (think that's what you call it) so that reducing distance by half literally results in twice the intensity.

Vis versa too – twice as far from the fixture results in half the intensity at the water surface. (The coverage swings in proportion too....either twice or half the diameter of coverage.)

Think about a bicycle wheel and its spokes. It's a pretty accurate, yet simple comparison.

 

[john.m.cole3]

So how do I convert to par? I have my 48 inch 6 bulb dimmable ati

How would you convert a 48 inch 6 bulb dimmable ati fixture with a surface lux reading of 34000?

Sorry weird posting

 

[saltyfilmfolks]

Sorry weird posting

Lol. I've had a lot weirder.

What tubes?

Coral plus have more par than a blue or purple

38 I recall for c+ 40 for b 40

Average both at 40 probably. I forget exactly now the numbers are in d riddle lux par conversion. Apogee lux par conversion draws some odd comparisons with uncommon combos.

But 40 is a good number usually it seems for c+ And 14k mh

50 seems good for a more blue t5 combo and 20k MH and is also the sun full sky number.

60 is is a meh led. As far as I've been able to research.

63 consistently in my research for mars Aqua btw. Belive it or not there's worse. Dana riddle set the led constant at 70 years ago in his paper.

With those numbers you can draw a good average across the board. And make it 45 55 or 65 if your curious of the difference.

 

[mcarroll]

How would you convert a 48 inch 6 bulb dimmable ati fixture with a surface lux reading of 34000?

The quick and dirty way I usually estimate is: 34,000 ÷ 50 = around 700 PAR.

These estimates will tend to be pretty conservative and I don't normally sweat it any further than this....unless you just want to. Read on...

If you look at the list of conversions Dana posted in Converting Lux to PAR and then sort the list by the conversion factor, you can see a statistical trend: the highest and lowest values on the list are clearly oddballs and outliers.

Unless you think a "Fusion Sulphur Lamp" or a "Westron Mercury Vapor" bulb should be considered "reef lights", throw them and the even more extreme ones out and you have a fairly narrow range of conversion factors roughly between 50 and 60.

So you might want to consider 34,000 ÷ [50|60] = around [700|600 PAR].

That's a pretty workable range for an estimate.

 

[john.m.cole3]

The quick and dirty way I usually estimate is: 34,000 ÷ 50 = around 700 PAR.

These estimates will tend to be pretty conservative and I don't normally sweat it any further than this....unless you just want to. Read on...

If you look at the list of conversions Dana posted in Converting Lux to PAR and then sort the list by the conversion factor, you can see a statistical trend: the highest and lowest values on the list are clearly oddballs and outliers.

Unless you think a "Fusion Sulphur Lamp" or a "Westron Mercury Vapor" bulb should be considered "reef lights", throw them and the even more extreme ones out and you have a fairly narrow range of conversion factors roughly between 50 and 60.

So you might want to consider 34,000 ÷ [50|60] = around [700|600 PAR].

That's a pretty workable range for an estimate.

Ok, that's cool. easier than I was anticipating.

 

[ksc]

How far was the meter from the light when you got 700? I just checked a 36" Sunpower yesterday with my par meter for someone.

 

[john.m.cole3]

That reading of 34,000 lux was 15" away from the center of the fuxture. 2x actinics at 100%. 3x blue + and 1x purple + at 75%

 

[ksc]

That lux reading is probably off by 50%. I'll fire up the Sunpower and give you a par reading @ 15".

 

[john.m.cole3]

good times! how many bulbs is your sunpower?

 

[ksc]

It's a 6 bulb Sunpower. At 15" directly in the center I got about 275. A few inches from the end I got 235. This was with the splash shield off. I'll let it warm up a bit and see if they go up a bit.

 

[john.m.cole3]

would we need to consider the length of the fixtures also?

 

[ksc]

Not really. I have read that the 36" bulbs put out a little less par than the 48", but it's negligible. For a 75g tank I'd hang it 6-8" off the water. Then you'll get your 5-600 par at the surface.

 

[saltyfilmfolks]

What meter are you using John

 

[ksc]

Are you sure the lux meter didn't read 3400? The lux meter shouldn't read the actinics very well and your other bulbs are only running 75%.

 

[saltyfilmfolks]

Are you sure the lux meter didn't read 3400? The lux meter shouldn't read the actinics very well and your other bulbs are only running 75%.

Curious too. If it's the app it's much more inaccurate. It's not using a photocell. It's a reflected light reading and not an incedent like par or lux.
Plus it has bigger color probs to consider because it's a camera and not a reflected light meter.