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.

[binford4000]

I ramped my LED's at 5% increase per week,My halides gave me about 250 par at the bottom of the tank and around 325 mid section. Your pic shows the sensor about 3/4 off the bottom.So your readings will be higher.At 3/4 with halides I was over 400.I set my LED's at 150 on the bottom and 225 in the mid section and worked them up from there.Befor the AEFW break out grwoth was fantastic with LED's and coloring was getting better then I'd seen it.I now am setting up this tank with a mix so I have turned the whites down to achieve a 225 reading in the center of the tank.It was suggest to me by calm sea quest to use a 25% error factor for the meter reading.In other words add 25% to your readings due to spectrum I believe.Either way I think he's pretty accurate with his info.I now am running both blues at 100% and whites at only 50% and am seeing good reaction from the survieing SPS and the paley's and zoa"s seam very happy.I think with your halide produceing such low levels your on the right track with starting very low and slowly increasing the intensity

[CableGuy]

I wish you were close Jim so I could borrow your PAR meter.... :sigh:

[nate_newton]

Looking great, and yes as Jim mentioned they're are no optics. You may want some kind of fan on the heatsink, it gets fairly hot. Oh and a side note, they're neutral white and not the cool whites you see on many fixtures.

[jimsflies]

Looking great, and yes as Jim mentioned they're are no optics. You may want some kind of fan on the heatsink, it gets fairly hot. Oh and a side note, they're neutral white and not the cool whites you see on many fixtures.

Wonder which is "better" neutral or cool white?

BTW- how many leds can one of these meanwells drive?

[nate_newton]

Wonder which is "better" neutral or cool white?

BTW- how many leds can one of these meanwells drive?

12 or 13 I think. I know 8 is minimum on the xr-e's.

[jimsflies]

Apparently when toggling the apex between manual and auto mode for the variable outlets (the ones the LEDs are plugged into), it causes the profile to restart...in other words if the profile is set to ramp the light level from 10-20% over 60 minutes instead of starting in the on position if it is in the middle of the photoperiod, it restarts the light back at 10%. The light levels to my eyes are barely noticeable between for example 10 and 20%.

What this means is, when I was measuring par the other day when I thought I was measuring at full intensity I was actually measuring somewhere near the beginning of the light program. I performed some additional measurements today with that in mind and what I found is that at 20% light, I am around 220. And at 100% on both blues and whites, the fixture is putting out ~620!

I had started out at 30%, but decided to back it down to 20% (changed it to that yesterday morning). I'm going to see how it does at that level...which is still a lot higher PAR than the corals were getting with my old halide bulb.

[binford4000]

Jim,I have a trick that I use that works well for tuening the lights.Leave the apex in auto and change your ramp times in profiles to 1 min.Once you get what you want just change the ramp times to what you had.There will be no change in your lights because it's already fully ramped.I am assueming your changeing this in your profiles of course.Hope that makes sense and helps.Have you considered raiseing your new led to get a wider spread?? Just an idea. Looks good tho

[rosebud161616]

Wonder which is "better" neutral or cool white?

BTW- how many leds can one of these meanwells drive?

I recently changed from cool to neutral on my white LEDs. The neutral gets a little bit better spectrum, but it also takes more blue to counteract it.

[jimsflies]

Jim,I have a trick that I use that works well for tuening the lights.Leave the apex in auto and change your ramp times in profiles to 1 min.Once you get what you want just change the ramp times to what you had.There will be no change in your lights because it's already fully ramped.I am assueming your changeing this in your profiles of course.Hope that makes sense and helps.Have you considered raiseing your new led to get a wider spread?? Just an idea. Looks good tho

Yeah...most of the time I just use my iphone to control the remote and unfortunately you can't change the profiles via the phone.

I think the key is to shorten the profile time frame...switch the outlet to another steady condition after the profile has completed rather than leave it in that profile. Here is what I ended up doing:

profile 1 ramps from 0 to 20% over 60 minutes

LED virtual outlet was set to from 07:00 to 22:00 to be in Profile 1 (so from 08:00 to 22:00 the leds are at 20%).

Instead use this:
profile 1 ramps from 0 to 20% over 60 minutes
profile 2 ramps from 20% to 20% over 0 minutes

Then LED virtual outlet is set from 07:00 to 08:00 to be in Profile 1
and from 08:00-20:00 to be in Profile 2.

That way if it is changed from manual mode to auto mode during the day, when it is switched back to manual mode, it will run in Profile 2 (20%)...rather than Profile 1 which restarts at 0% and takes an hour to get back to 20%.

Hope that makes sense.