PAR for the course
Posted 06/29/2012 at 09:33 PM by Spaced Cowboy
Tags build
So having gone with the AI Sols, I wanted to see how well they were lighting the tank. The goal was always to have darker areas and more well-lit areas, I didn't want to blast everything in the tank with bright light, I wanted something that looked a little more natural.
So I started looking around for PAR meters - there's a couple of DIY projects but nothing calibrated and "ready to go", so I caved and looked at the professional ones. Apogee's meters seem to be the normal ones used, but after tax they were coming out at $400 or so. However... I noticed that they're calibrated to 5.0 µmol m^-2 s^-1 per mV, which means you just need to connect them up to a multimeter that reads millivolts accurately, and multiply by 5 to get the PAR rating. Excellent - the sensors are a lot cheaper than the full-blown meter, so that's the way I went.
Here's the results:
[IMG]http://0x0000ff.com/imgs/fishtank/par.JPG[/IMG]
Sorry for the large image, it's a wide tank
Just below the water-level and in the center of the tank, it's at 960 PAR, which is pretty good Some of the numbers look a bit weird, but they're more to-do with the fact that it's hard to get a sense of depth from the photo, and if the reading is towards the front or back of the tank, it's much lower than it looks like it ought to be in 2D.
So, I guess the question is: is that good enough ? There seem to be areas that are good, but my gut feeling is that a bit more might be useful. There's another 2 AI units sitting in the shed and I could slot them into the support bar easily enough... That's just a gut feeling though, I don't really know what PAR I need, in order to keep corals... Anyone got any suggestions ?
BTW, the support beam isn't bending, it's an artifact that came in when I straightened the photo to make the tank look level. I'm not a great photographer
So I started looking around for PAR meters - there's a couple of DIY projects but nothing calibrated and "ready to go", so I caved and looked at the professional ones. Apogee's meters seem to be the normal ones used, but after tax they were coming out at $400 or so. However... I noticed that they're calibrated to 5.0 µmol m^-2 s^-1 per mV, which means you just need to connect them up to a multimeter that reads millivolts accurately, and multiply by 5 to get the PAR rating. Excellent - the sensors are a lot cheaper than the full-blown meter, so that's the way I went.
Here's the results:
[IMG]http://0x0000ff.com/imgs/fishtank/par.JPG[/IMG]
Sorry for the large image, it's a wide tank
Just below the water-level and in the center of the tank, it's at 960 PAR, which is pretty good Some of the numbers look a bit weird, but they're more to-do with the fact that it's hard to get a sense of depth from the photo, and if the reading is towards the front or back of the tank, it's much lower than it looks like it ought to be in 2D.So, I guess the question is: is that good enough ? There seem to be areas that are good, but my gut feeling is that a bit more might be useful. There's another 2 AI units sitting in the shed and I could slot them into the support bar easily enough... That's just a gut feeling though, I don't really know what PAR I need, in order to keep corals... Anyone got any suggestions ?
BTW, the support beam isn't bending, it's an artifact that came in when I straightened the photo to make the tank look level. I'm not a great photographer
Total Comments 4
Comments
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What are your tank's dimensions?Posted 07/05/2012 at 09:57 PM by TheFishTeen 
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Here's Sanjay Joshi's site. He's a well respected Phd lighting guru, who is in the reef hobby. He created a par calculator. He literally tested all metal halide hqi bulbs on the market.
I have a feeling you've a great amount of par, but you should take a look to make sure
http://www.manhattanreefs.com/lighting
Here's some LED tests (note that the maximum par with 130 watts of led is 550.
http://marine-engineers.org/2012/01/...g-interpreted/Posted 07/06/2012 at 06:00 PM by IridescentLily
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The tank is 8' by 2' by 2', and there's only 3 of the AI blues suspended about 12" off the top of the water surface, arranged lengthwise (so the longer parts of the Sols are parallel to the longer side of the tank) down the tank.Quote:Originally Posted by TheFishTeen
What are your tank's dimensions?Posted 07/18/2012 at 06:39 PM by Spaced Cowboy
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Thanks very much - I'll take a lookQuote:Originally Posted by IridescentLily
Here's Sanjay Joshi's site. He's a well respected Phd lighting guru, who is in the reef hobby. He created a par calculator. He literally tested all metal halide hqi bulbs on the market.
I have a feeling you've a great amount of par, but you should take a look to make sure
http://www.manhattanreefs.com/lighting
Here's some LED tests (note that the maximum par with 130 watts of led is 550.
http://marine-engineers.org/2012/01/...g-interpreted/
I've actually just sold the two SOL whites I had hanging around, so there's some spare cash for lighting burning a hole in my pocket
Cheers
SimonPosted 07/18/2012 at 06:41 PM by Spaced Cowboy
