PAR Meter Question

[csmith]

As it turns out the search function still won't allow 3 letter word searches (CO2, Wet Dry, PAR, etc). Can someone inform me as to what exactly I'm looking for in a PAR meter for my aquarium(s), or better yet just give me a link to one that is inexpensive (I understand the term is relative) yet accurate? For what I'm wanting to do (low light, CO2, foreground only plants and maybe some Anubias or Crypts), I'd like actual numbers rather than guesstimates. Thanks in advance.

[Left C]

I think that some folks use the Apogee Instruments MQ-200 quantum meter. http://www.apogeeinstruments.com/quantum/index1.html

[csmith]

Thank you for that, Left C. Before I let my assumptions rule, would the model "SQ-120 electric with 5m lead" be all I need? To say deciphering the owners manual is giving me issues is an understatement.

Edit: I believe I was mistaken. I'm seeing meters and sensors seperated. Are both a seperate must-purchase?

[Left C]

Check out the information for the MQ-200. It is what Apogee recommends for aquarium use. I don't know if you will want the leveling plate or want the communication cable that is required for data download to a computer

[csmith]

Got that part. Is the meter and sensor a separate purchase, or is the MQ-200 all that's needed?

Edit: I'm taking this as the meter is the box and it registers the information, and the sensor is the orb with the cord that takes the reading in the tank. Perhaps I'm complicating this?

[Left C]

AquariumSpecialty.com sells the meter and the sensor as an unit. The AC-100 and software are an option.
http://www.aquariumspecialty.com/con...ght-par-meters

EDIT: Did you see this part of the manual? It shows that the meter and the sensor come together: http://www.apogeeinstruments.com/man..._300manual.pdf

[csmith]

Ah, missed that one. I was looking at the spec sheets. Last question, these things are waterproof or are readings taken in an empty tank?

As always, thanks for the help Left C. First regulators, now this.

[gsjmia]

I had previously read that you could just buy a sensor for 139 and a cheap multi-meter and multiply the milivolts by 5 to get the PAR. After speaking the the Apogee tech support guy, he said that yes this combo would do the same thing as the more expensive meter, but that the only drawback is that you couldn't data log. The leveling plate is more for outdoor sun use to make sure you get the proper orientation throughout the range of the sun during the day-it is not necessary, won't fit in the aquarium and you can just attach it to a plastic stick and move it around to measure the highest reading.

I bought the Apogee SQ-120, which is the sensor only (electric calibration): http://www.apogeeinstruments.com/quantum/index1.html. I bought this Equus auto-ranging meter at Amazon $17: http://www.amazon.com/gp/product/B000EVYGZA

That and a pair of jumpers to connect the leads and it works fine--Apogee PAR meter for $150.

The Equus meter will auto range to milivolts-just multiply times 5 to get the par.

I also was worried about calibration of the sensor-the Apogee tech support guy said that the sensor will lose about 2% per year when in the sun all day--under electric lights it should never need to be calibrated--especially if used only periodically.

There is a weird bulge in the sensor's cable about 18 inches from the sensor and it is in a rubber shrink wrap. I was worried about submerging that part. The tech support said it was "the in-line electronics and is heat shrinked with adhesive wrap and is ok to submerge".

This set-up seemed clunky and rinky dink until I got familiar with reading the meter-I kept having trouble getting it on the right settings, but once I got the meter setting right (DC volts) and saw the different responses in different places (shade vs. right under the light), I could see that it was working correctly and I was very pleased.

Turns out I had 80 Micromole at substrate only in the very front center substrate and the rest of the substrate was 30-50 Micromoles. At the surface it was 200 Micromoles.

I took pictures, if anyone is interested let me know and I will post (if I can find the camera).

FYI, on the sensor, there are three strands: red, black and a clear wire with silver strands. The Red goes to the Plus on the meter. The Black is the negative and the clear is the ground-twist them together and connect to the Negative on the meter. Turn the meter to DC volts.

I mounted it on the end of an algae scrubber handle with the provided nylon screw.

46 Bowfront
4X39w Tec 5 light 8" inches above tank and 24" from substrate.

[Tom Barr]

I had previously read that you could just buy a sensor for 139 and a cheap multi-meter and multiply the milivolts by 5 to get the PAR. After speaking the the Apogee tech support guy, he said that yes this combo would do the same thing as the more expensive meter, but that the only drawback is that you couldn't data log. The leveling plate is more for outdoor sun use to make sure you get the proper orientation throughout the range of the sun during the day-it is not necessary, won't fit in the aquarium and you can just attach it to a plastic stick and move it around to measure the highest reading.

I bought the Apogee SQ-120, which is the sensor only (electric calibration): http://www.apogeeinstruments.com/quantum/index1.html. I bought this Equus auto-ranging meter at Amazon $17: http://www.amazon.com/gp/product/B000EVYGZA

That and a pair of jumpers to connect the leads and it works fine--Apogee PAR meter for $150.

The Equus meter will auto range to milivolts-just multiply times 5 to get the par.

I also was worried about calibration of the sensor-the Apogee tech support guy said that the sensor will lose about 2% per year when in the sun all day--under electric lights it should never need to be calibrated--especially if used only periodically.

There is a weird bulge in the sensor's cable about 18 inches from the sensor and it is in a rubber shrink wrap. I was worried about submerging that part. The tech support said it was "the in-line electronics and is heat shrinked with adhesive wrap and is ok to submerge".

This set-up seemed clunky and rinky dink until I got familiar with reading the meter-I kept having trouble getting it on the right settings, but once I got the meter setting right (DC volts) and saw the different responses in different places (shade vs. right under the light), I could see that it was working correctly and I was very pleased.

Turns out I had 80 Micromole at substrate only in the very front center substrate and the rest of the substrate was 30-50 Micromoles. At the surface it was 200 Micromoles.

I took pictures, if anyone is interested let me know and I will post (if I can find the camera).

FYI, on the sensor, there are three strands: red, black and a clear wire with silver strands. The Red goes to the Plus on the meter. The Black is the negative and the clear is the ground-twist them together and connect to the Negative on the meter. Turn the meter to DC volts.

I mounted it on the end of an algae scrubber handle with the provided nylon screw.

46 Bowfront
4X39w Tec 5 light 8" inches above tank and 20" from substrate.

This is a good cheaper semi DIY option.
Will save you some $ for sure.

[jaafaman]

I had previously read that you could just buy a sensor for 139 and a cheap multi-meter and multiply the milivolts by 5 to get the PAR. After speaking the the Apogee tech support guy, he said that yes this combo would do the same thing as the more expensive meter, but that the only drawback is that you couldn't data log...

I'm working on one of these in the meantime:

Arduino and the Taos TSL230R Light Sensor: Getting Started

although the second part of the article isn't really necessary, as we don't usually convert from energy to illuminance

Arduino and the TSL230R: Photographic Conversions

I intend to "map out" the light profile of an 80-gallon's landscaping across time with a few of these, among other sensors and controllers (CO2/pH, dosing, etc.), using an Arduino-specific control network...