Par metering a Led light system

[Company101]

Ok. So I went to rapidled.com

Bought a bunch of leds. Built my own lights

Now I just bOught a par meter.

I run a storm controller.

The dimmers are set to the specifics of rapid leds website.

I seem to have a lag in growth. I have been slowly turning up my light.

But I want to know if there is a chart. Or number references for an ideal led lighting system?

 

[Mpierce]

Most people shoot for 100-200 par on their sand bed for a mixed reef. You can crank it up higher if you go slow. What types of corals do you have? What lighting system were you using before. Often there is an acclimation time when your corals are getting used to the new light and may not show as rapid of growth.

Best thing is to take it slow and ramp them up a few percent a week. Easy to fry your corals and kill them. They will live much, much longer under not enough light vs too much.

 

[tankstudy]

What types of LEDs (RB/W/Red/Green,etc.) did you get, how many and what intensities are you running the individual colors at?

 

[Company101]

I run a 2-1 with royal blues and neutral white

40 royal blues
20 neutral whites
8 UV
4 limes

Also 8 royal blues for night time light

I run a storm controller.

 

[Company101]

 

[Mpierce]

From the looks of what you have going (soft corals and the clam from what I can tell) I would go for 300-400 par at the top of your rock structure and try to maintain 100 par on the sand. Slowly turn things up if it seems to be going well. If things are looking poor at those light levels I would turn it down a bit.

 

[Company101]

I have lps and softies. And Zoanthids. I want sps.

 

[Mpierce]

Most SPS seem to thrive between 300-600 par. It is just a balancing act with a mixed reef trying to make everyone happy. Start slow and most corals will adapt to higher PAR levels.

 

[Company101]

Should I attempt to add more color to what I have ?

 

[tankstudy]

I run a 2-1 with royal blues and neutral white

40 royal blues
20 neutral whites
8 UV
4 limes

Also 8 royal blues for night time light

I run a storm controller.

I would recommend getting atleast 10 BLUE LEDs in to the mix. You can drop 5 Royal blues and 5 neutral whites. Although neutral whites have some wavelengths in the 450-470 nm, the blue LED's primary/peak wavelength is 470 nm. Royals blue primary/peak is at 450 nm so runing Royal Blues with Blues will cover you pretty well in the blue spectrum similar to T5 bulbs. In the ecotech radion's AB+ spectrum, Royal blue and Blue run at 100% intensity while white runs 25% or less. In your case I would run it at 25% because you don't have any greens/red LEDs in the mix. Running the neutral whites at 25% will help give you these colors. When I was using RapidLEDs, I ran pretty much a similar intensity pattern to get good growth.

As for par, once you set the intensities correctly, a 150 par can grow SPS pretty easily. I would leave the sand bed at 75-100 par for your zoa/paly and softies. Keep in mind, you won't see results instantly. Your corals will need to adjust to the intensities and once that happens, growth will follow, this can take several months depending on the species of coral you have. Tinker too much and your coral can stress out and become stunted/die.

 

[Mpierce]

I think you have it pretty well covered. The neutral whites cover the red/yellow spectrum well. The limes help the light look brighter to the human eye, blues, royal blues, and violet are what corals crave. I would Run all the colors together during the daylight hours. Just tune them into the spectrum you like and where the corals seem happy.

I just noticed you don't have any regular blues, probably want some of those.

 

[mcarroll]

Your lights are quite high up off the tank unless you're running some strong lenses, so you might not be getting the levels in the tank you suspect you are.

Have you taken any PAR measurements yet? I'd most like to see what you get across the surface in air.

Readings in water will also be interesting later.

 

[mcarroll]

Is that a slide projector under the tank? So retro!!!

 

[Company101]

I was just reading again about the height of the lights. And now I do seem to think they are pretty high.

 

[Company101]

Is that a slide projector under the tank? So retro!!!

That's a cheap fan from Walmart. Cheap chiller.

 

[tankstudy]

I was just reading again about the height of the lights. And now I do seem to think they are pretty high.

For LED's the higher the better IMO.

This will produce better mixing of the wavelengths. You do have to run them at higher intensities but you don't have to worry about some corals only getting a limited amount of the proper wavelengths.

 

[Company101]

Ok update on this. I finally got my hands on a biotech 3000. And after some time figuring it out. I finally got it going. I lowered my whole lighting grid to 13" off the water and the par measurement I am getting is 250.

The drivers I am using to control the leds have been turned down a. It when I first installed them. This measurement is a collective of all the leds on at once. And on the storm controller they are at maximum.

Is there any factor I need to think of when adjusting par. With this meter?

 

[mcarroll]

My guess is that's on the low end of "just fine".

Like @Mpierce said, and since you have a capable meter, check for around 50-100 PAR at the sand bed. (More is OK, but not "better".)

For the most correct PAR numbers, I think you might have an emersion correction factor as well as some wavelengths correction factors that you can apply when you start sampling underwater. (Isn't that the same as the older Apogee sensor so it would use their corrections?)

Don't worry if you don't have all that info or don't feel like the bother though....you'll still get measurements that are in the ballpark and correct relative to each other.

 

[BigJohnny]

Know this is old but the immersion correction for the btm-3000 which uses the old quantum apogee sensor, is x1.08

There are some spectrum corrections you can apply but difficult to do so accurately unless you know exactly what portion of your light falls within spectrum AND happens to be hitting the PAR sensor. I believe the 1.08 immersion correction is sufficient.