Finally broke down and got a PAR meter

[malawian]

Its driving me nuts, my params are pretty much perfect but a number of things are really unhappy and my guess is light. I just have no idea where my light is, especially with no optics and a diffuser. Just too many variables.

 

So finally I did it because I just have to know.

 

Quick question for those of you who have one, do you know if you can measure each channel separately and add them at the end? I know there is a correction factor for different colors so in my mind it would be more accurate to log each color separately but I dont know if PAR is additive like that.

[Nanofreak79]

I've always done them with all channels on. I would think that you could do them separate, although do you run them that way? I would do a full reading of what I was using. Blues read lower, obviously as I'm sure you've read.

 

 

 

 

I did mine with a meter and used it every hour on the hour until lights out. This gave me numbers for all different peaks and intensity.

[malawian]

I've always done them with all channels on. I would think that you could do them separate, although do you run them that way? I would do a full reading of what I was using. Blues read lower, obviously as I'm sure you've read.

 

 

 

 

I did mine with a meter and used it every hour on the hour until lights out. This gave me numbers for all different peaks and intensity.

no definitely not but since Appogee gives exact correction values for different wavelengths I could account for those differences. it probably isnt a big enough difference for it to matter though?

[evilc66]

If you measure with all channels on, just be aware that you will be reading low. The amount of blue/violet light compared to other wavelengths will change the error factor (high blue ratio will increase the error). If you want a more accurate reading, measure each channel separately, apply the correction factor for the particular wavelength, then add them all together.

[malawian]

If you measure with all channels on, just be aware that you will be reading low. The amount of blue/violet light compared to other wavelengths will change the error factor (high blue ratio will increase the error). If you want a more accurate reading, measure each channel separately, apply the correction factor for the particular wavelength, then add them all together.

 

perfect, thats what I was hoping I could do although it will be tricky with my red green cyan 3-ups since I cant turn off each one individually. I will probably just guestimate that one since it should be a small amount of the total light, but this is one of the things I hope to find out,

[evilc66]

You should be fine taking the PAR values at face value for those 3-ups. None of them fall into the low sensitivity zone below 470nm. It's really only blue, royal blue, and violet that you need to start adding a correction factor.

[Subsea]

I have had a PAR meter for 20 years. Yours is more sophisticated in that you can separate spectrum. However, it will not grow the coral no matter how sophisticated your meter or how full spectrum your lighting is. Between Dana Riddle and Sanjay, these two scientist have written much about spectrum response. There is much that is unknown about different corals spectrum response. Some corals never adjust to artificial lighting, some do. While not an absolute barometer, research the depth that the coral is most abundant in nature. This will tell you much about what it needs. A PAR meter is not required to do that, but it is fun to play with our toys.

Patrick

[Subsea]

I will assume that your lights are DIY. Of recent, I am doing research with different DIY led. I prefer no optics on the diode as it enhances diffusion. What are you using for a light diffuser?

[malawian]

I have had a PAR meter for 20 years. Yours is more sophisticated in that you can separate spectrum. However, it will not grow the coral no matter how sophisticated your meter or how full spectrum your lighting is. Between Dana Riddle and Sanjay, these two scientist have written much about spectrum response. There is much that is unknown about different corals spectrum response. Some corals never adjust to artificial lighting, some do. While not an absolute barometer, research the depth that the coral is most abundant in nature. This will tell you much about what it needs. A PAR meter is not required to do that, but it is fun to play with our toys.

Patrick

Certainly, the PAR meter only reveals a tiny part of the equation. My biggest problem is that I have very little to use as a reference point because my fixture is DIY. I dont know if I have 10 PAR or 1000 on the sandbed, I just dont have a clue. Since I dont know if Im high or low for intensity Im scared to adjust it because what if I move it in the wrong direction and everything starts to die?

 

I will assume that your lights are DIY. Of recent, I am doing research with different DIY led. I prefer no optics on the diode as it enhances diffusion. What are you using for a light diffuser?

 

Yes they are DIY, there is a lot of info about them in my build thread. I was using 60 degree optics but have since removed the optics and added a diffuser. The diffuser is just a standard flourescent light diffuser panel available at any lows or home depot which I cut to fit the fixture.