So I've been trying to rent a PAR meter for some time and BRS ended theirs. I see they now have an option labeled as wet tested or something along those lines. However I've been having issues with growth for a while, slow to non existent. I initially blamed it on my DIY LED light fixture not having enough par for my larger tank. I bought a new Photon v2+ and used BRS to set my baseline readings for SPS and then lowered them a touch for a mixed reef. Over a month later, still little to no growth. All parameters were in check. Nitrates and phosphates were a bit low so I worked on upping them. Got a little bit of growth over a few weeks but nothing like in the past. I finally decided to bite the bullet and buy the Apogee SQ-120 and wire it to a multi-meter. My Initial reading at the top of the rockwork (after x5 and a 1.33 correction) I was showing 550-650 par at the top of the rock work!! I have a few acros and montis and they weren't bleached but didn't show great color. I have lowered my light 35% just to get to the recommended 250-350 par range. I couldn't believe it was that high! I then watched the awesome MACNA talk that @DanaRiddle did about lighting, flow, and photosynthesis. At the higher readings, photosynthesis basically stopped until the lights dimmed to evening. This only gave me about an hour of usable light per day. Now that the PAR is in an acceptable range, I am really hoping I can see some growth and deeper colors.
Moral of the story, if you have LED lights and have an extra 200 to spend, I highly suggest measuring your PAR.
Moral of the story, if you have LED lights and have an extra 200 to spend, I highly suggest measuring your PAR.