avianman
New Member
I’m using these instructions and it doesn’t go back once I calibrate the first time. Also it gives an insanely higher number with the bag on. I don’t get it.
Yeah - most of the posts on here either didn't read the instructions or they tried it before instructions were printed. I get it, we are all excited to try it, but if you don't set it up correctly it won't give correct readings.
To clear a few things up -
This app is very accurate for measuring PAR, even underwater. The problem is that you need to calibrate it first to your bag, and then adjust to account for the water (1.32).
Here are the instructions again: Photone App adjustments for reef measurements
Everyone's plastic bags are going to be different, which is why you must calibrate the measurements for whatever bag you are using first and then adjust by using the immersion effect correction factor of 1.32
You must use the diffuser. Even if your light has a diffuser on it. You are measuring the par coming through the diffuser, which is being considered, so even if your light has 10 diffusers, you still need to add a diffuser that is made from 80gsm printer paper. That's basic printer/copier paper. No, you can't use something else unless you are going to recalibrate.
You can't change the order of that procedure - that will change the results.
You must place the phone in the exact same place, and hold the phone at the exact same level, in order to calibrate. This is true for all par meters, but especially true because of the way the camera is on the phone. Tilt the phone 15 degrees and you will get a different reading. That's how the light works.
Yes, you must select the light source, and LED lighting has three options - full spectrum, Red/Blue, and White/Blue. They are an additional $5.99 each, but once you buy that you get it forever. You CAN pay $29.99 for the "pro" version and get all of it unlocked for a year. Pro settings also allow you to disable hold mode.
So far, no one has selected white/blue for their measurements, which is interesting. Yes, our white lights are full spectrum but I have yet to meet a reefer who isn't adding some sort of additional blue lighting.
Here's the thing - you can't "just try and do it using the 'sun' selection instead of paying $5.99 for the LED selection"
You can't "just try it without the diffuser"
You can't "Just do it without converting" or "do it without calibrating"
All of these things change the results, but it isn't a uniform change (say - off by exactly 20) but rather, an exponential change, which means one may read 1000 PAR at the surface pre-calibrated but 600 PAR at the surface before calibration.
If you follow the instructions, you will have a PAR meter in your pocket for either $30/year or $6 if you want to go cheap.
In my readings, the app was accurate within 5% of the apogee MQ-510 par meter.
Remember - this was developed by and for cannabis growers - the only people more dedicated than reefers to their lighting!
Just as an FYI - I grow plumeria as a hobby. Plumeria is a fascinating plant that grows in tropical environments. Since I live in zone 6b, I have to use artificial lighting (full spectrum - no added blues!) to grow my plumeria. I need 800-1000 PAR to get them to flower, so I need a good par meter. I use this app because it is easy and fast and accurate - if you use it right
Good luck!
