Measuring Kessil A360WE PAR

Bozoman · Oct 2, 2016

I apologize. The rant really wasn't aimed at you specifically, more to the general population of "PAR chasers". It is what comes to mind nearly every time I see the word PAR mentioned in a forum thread. I can completely relate to the OCD aspect of control and the scientific curiosity as well as the tech nerd aspect of testing/buying new gear and tools. Enjoy your new toy! ;)

DT Prime · Oct 2, 2016

Bozoman said:
I apologize. The rant really wasn't aimed at you specifically, more to the general population of "PAR chasers". It is what comes to mind nearly every time I see the word PAR mentioned in a forum thread. I can completely relate to the OCD aspect of control and the scientific curiosity as well as the tech nerd aspect of testing/buying new gear and tools. Enjoy your new toy! ;)

No worries no offense taken, thanks for joining the thread! I think between how much emphasis gets put on "proper lighting" and then how many variables there are with lighting sources, measuring, and all the different corals preferences, it's one of those things where there's enough outside information to make people question if they're doing it "right". Plus if all your levels look normal I can understand how lighting would be the first thing you go to in terms of blame if something isn't going well.

Hopefully these meters continue to advance and get cheaper so some of the mystery can be taken out of it. While I doubt we'll get to a point where it's like salinity and you can say it should be around 1.026 with some confidence it would be nice to have some general ranges you can aim for and monitor like with chemical tests. That said this meter was only $150 after 25% off on F&S, so really one of the cheaper pieces of equipment I've bought so far!

Planning on calling them tomorrow to see what they say about use with LED before I start really modeling my tank, which I should have just done in the first place.

Bozoman · Oct 2, 2016

I would highly recommend finding set spots in the tank at 2-3 different depths so you can regularly measure at the same spot (assuming your lights are in a set spot) and keep track of the light and its ability to penetrate the water. This can highlight coloring in the water that can otherwise be hard to see to the naked eye, and tell you when its time to fire up the carbon reactor and avoid a larger reduction in PAR. It doesn't take much tint to reduce the lights ability to penetrate.

DT Prime · Oct 2, 2016

Bozoman said:
I would highly recommend finding set spots in the tank at 2-3 different depths so you can regularly measure at the same spot (assuming your lights are in a set spot) and keep track of the light and its ability to penetrate the water. This can highlight coloring in the water that can otherwise be hard to see to the naked eye, and tell you when its time to fire up the carbon reactor and avoid a larger reduction in PAR. It doesn't take much tint to reduce the lights ability to penetrate.

Awesome advice, that's exactly the kind of stuff I was hoping to use it for down the line.

andys · Oct 2, 2016

DT Prime said:
No worries no offense taken, thanks for joining the thread! I think between how much emphasis gets put on "proper lighting" and then how many variables there are with lighting sources, measuring, and all the different corals preferences, it's one of those things where there's enough outside information to make people question if they're doing it "right". Plus if all your levels look normal I can understand how lighting would be the first thing you go to in terms of blame if something isn't going well.

Hopefully these meters continue to advance and get cheaper so some of the mystery can be taken out of it. While I doubt we'll get to a point where it's like salinity and you can say it should be around 1.026 with some confidence it would be nice to have some general ranges you can aim for and monitor like with chemical tests. That said this meter was only $150 after 25% off on F&S, so really one of the cheaper pieces of equipment I've bought so far!

Planning on calling them tomorrow to see what they say about use with LED before I start really modeling my tank, which I should have just done in the first place.

Just curious what device do you have to measure par ?

DT Prime · Oct 2, 2016

andys said:
Just curious what device do you have to measure par ?

The Biotek Marine BTM-3000 shown in the original post

gus6464 · Oct 3, 2016

The biotek unit is basically an apogee sq200. It is fine for 450nm. Where the sq200 lacks is 420nm and below. This is a problem if you are pushing heavy violet or actinic bulbs. If you are in this camp a lux meter is absolutely useless as well. Why? Because it will be off by a massive amount at this wavelength. And by massive I mean 8x in 405-410.

DT Prime · Oct 3, 2016

gus6464 said:
This is a problem if you are pushing heavy violet or actinic bulbs. If you are in this camp a lux meter is absolutely useless as well.

Excuse the noobery but does that apply to the lights I'm using?

gus6464 · Oct 3, 2016

DT Prime said:
Excuse the noobery but does that apply to the lights I'm using?

Well based on this

It depends on the color setting you choose but even at the most concentration it's not much but it does have some decent output at sub 400nm. As a rough estimate I would say whatever number you get on the biotek add around 10% and you will be in ballpark. This is of course based on a bluer setting as those pump out the violet more.

DT Prime · Oct 3, 2016

gus6464 said:
Well based on this

It depends on the color setting you choose but even at the most concentration it's not much but it does have some decent output at sub 400nm. As a rough estimate I would say whatever number you get on the biotek add around 10% and you will be in ballpark. This is of course based on a bluer setting as those pump out the violet more.

Awesome thanks for explaining that! Still planning on calling the company today and will report back any additional info they provide.

Thanks again to everybody who has chimed in so far too!

DT Prime · Oct 3, 2016

Here was the response I got from Biotek, not exactly verbose but seems to confirm what others have said, they will work with a slight modifier applied. Now to figure out which to use when :)

"The numbers are accurate to a point but you need to use a multiplier with blue light. For 20K lighting multiply the PAR numbers by 1.2. For 15K lighting use a multipler of 1.1.
We still sell a lot of the BioTek Marine PAR sensors and converting the numbers is very simple without having to spend over $500.00 for a meter that adjusts for LED spectrums."

Thor2j · Oct 9, 2016

DT Prime said:
Here was the response I got from Biotek, not exactly verbose but seems to confirm what others have said, they will work with a slight modifier applied. Now to figure out which to use when :)

"The numbers are accurate to a point but you need to use a multiplier with blue light. For 20K lighting multiply the PAR numbers by 1.2. For 15K lighting use a multipler of 1.1.
We still sell a lot of the BioTek Marine PAR sensors and converting the numbers is very simple without having to spend over $500.00 for a meter that adjusts for LED spectrums."

This is why u buy an Apogee Sq-520 for $345 and plug into a lap top.

mcarroll · Oct 10, 2016

Thor2j said:
From what I've read it's not really that accurate for true par readings. The good thing is you can measure your tank and the numbers are only references so accuracy doesn't matter.

...which is why a lux meter also works. :)

mcarroll · Oct 10, 2016

DT Prime said:
Here was the response I got from Biotek, not exactly verbose but seems to confirm what others have said, they will work with a slight modifier applied. Now to figure out which to use when :)

"The numbers are accurate to a point but you need to use a multiplier with blue light. For 20K lighting multiply the PAR numbers by 1.2. For 15K lighting use a multipler of 1.1.
We still sell a lot of the BioTek Marine PAR sensors and converting the numbers is very simple without having to spend over $500.00 for a meter that adjusts for LED spectrums."

This is a conversion factor just like you'd use on a lux meter when you've calibrated it against a PAR meter.

2¢

Product Review: Lighting for Reef Aquaria: Tips on Taking Light Measurements

mcarroll · Oct 25, 2016

DT Prime said:
my lights are 2 A360WE's mounted 15" apart and 6.5-7" from water surface and a RSR 250:

Any chance you could turn your lights to 100% intensity and throw some measurements up for the water surface as well as just under it?

This would give me and others a more useful reference. :)

DT Prime · Oct 25, 2016

mcarroll said:
Any chance you could turn your lights to 100% intensity and throw some measurements up for the water surface as well as just under it?

This would give me and others a more useful reference. :)

Unfortunately I'm out of town unexpectedly but hoping to be back this weekend, will get this for you when I'm able for sure though. Can tell you from my initial tests they will be very high at the surface but my lights are also 7-8" off the surface, I know a lot of people usually have them higher.

DT Prime · Oct 30, 2016

mcarroll said:
Any chance you could turn your lights to 100% intensity and throw some measurements up for the water surface as well as just under it?

This would give me and others a more useful reference. :)

Water surface at 100/100 is 750-850 par, 5"-6" or so under is roughly 300, 10" about 175-200, 18" about 125-150