Measuring PAR -->Acclimating Livestock

[jimsflies]

I changed out my 150-watt halide this weekend for a used DIY led fixture I purchased from @nate_newton . The fixture consists of 16 Cree's (3-watts) ...8 blues and 8 whites driven independently by MeanWell ELN-60-48D drivers. It should also be noted the fixture does not have any optics. I have the fixture connected to an Apex controller so I can control the intensity of the leds over the course of the day. I'm planning to use this to also start the leds at a lower intensity in an attempt to acclimate my corals.

The existing halide bulb is a Coralife 150w 14k and as I confirmed today, is in dire need of replacement. It only measured 60 uE/m2/sec. Compared to when it was only a couple months old it was 330.

Photo with halide:




My original thought was to initially run the leds at 30% intensity and ramp up from there. I found today that run both blues and whites at 30% is about 165 uE/m2/sec. So more than double what the old halide is producing.

I would say the color is similar to a 20k radium:


I also measure the par with all leds at 100% power and it measure around 365 uE/m2/sec.

So I think based on the reading at 30%, I probably better start a little lower. I'm going to check it at 20% tomorrow and check the output. The question is, how long should it take to acclimate the corals to higher lighting levels. It would be nice to be proactive rather than reactive (i.e., increasing it until I see signs of damage to the corals before knowing they weren't ready). Mostly right now I am keeping soft corals (leathers) and anemones.