PAR Rating in My Acropora Dominated Tank

[Tete]

A friend of mine stopped over today to give me somme PAR readings. I have 2 250 Watt DE MH bulbs in Hamilton Reefstar pendants using the Hamilton magnetic HQI ballasts.

I have a 65 gallon tank which is 36 wide, 18 front to back and 24 inches deep. The lights are 13 inches above the water.

I didn't take many but here are some readings using 14K Phoenix bulbs and two Kessil A150W Ocean Blues. The following readings are down the center.

440 just above the water
340 just below the surface
240 halfway down.
180 about 3 inches above sand bed

With a 20K Ushio on the left and 20K Hamilton on the right and the Kessils
Ushio Side
230 just below the surface
160 halfway down

Hamilton Side
300 just below the surface
200 jalf way down.
140 about 3 inches above sand bad

Kessil A150W Ocean Blues only
100 just below the surface
80 halfway down

My acros have great color and growth. Before, the Phoenix were just 5 inches above the water and the color wasn't as nice. I always assumed I had too much par before.

I think this tells me that acros really don't need super high PAR values, at least when using metal halides.

 

[msaba]

yes I am guilty of 'more is better' with light and have been 'burned' before! Always interested in what acros color up well at what par areas in your tank. A FTS with par values superimposed would be neat to see…

Mark

 

[ssscuz]

This topic seems to come up all the time.
It will depend on the corals as to how much light they can handle, some corals that are collected are under 1mtr of water with the sun beating down so will need far more par than a deeper water specimen.
I personally don't believe we can give coral enough light with a t5/led setup. The 400w halide setups sure pack some punch so I'm sure they can

 

[ridetheducati]

 

[Tete]

Below is a FTS. The purple numbers are the PAR ratings of the 250W Phoenix DE's.

The other numbers are the following corals:

1) PC Rainbow
2) Battlecorals Flyyy me to the blue moon humilis
3) Sunset milli
4) Green slimer
5) A Crayola type plana
6) ORA blue milli
7) Tyree ice fire echinata
8) a blue tipped tenuis
9) Oregon tort
10) ORA blue German blue polyp acro
11) ORA Hawkins
12) Tyree red dragon

 

[trueblackpercula]

The Par readings you are getting are good but LEDs are double if that is what you are looking for.

 

[ridetheducati]

The Par readings you are getting are good but LEDs are double if that is what you are looking for.

Not sure I understand, LEDs are double?

 

[trueblackpercula]

Hope this helps
http://www.reefcentral.com/forums/showthread.php?t=2346704

http://www.reefcentral.com/forums/showthread.php?t=2272079

 

[ridetheducati]

Hope this helps
http://www.reefcentral.com/forums/showthread.php?t=2346704

http://www.reefcentral.com/forums/showthread.php?t=2272079

I just ask that you rephrase your comment, explain it like I am six years old. You lost me with the word "double". Not sure why you linked to other threads.

Asking for a little clarity.

 

[Tete]

I read some of those posts and it did clarify it for me.

 

[jfuka78]

It doesn't double, for the majority of us there is no way to measure par on led. I use apogee to get a rough idea.

 

[PrangeWay]

From Apogee..
http://www.apogeeinstruments.com/light-intensity-measurements-for-light-emitting-diodes-leds/
also
http://www.apogeeinstruments.com/content/Quantum Sensors-LEDs.pdf

I'm not sure where the "double" ever came from, but certainly not Apogee.

I've found using Apogees error correction works relatively well as I did with my meter when I moved from MH/T5's to LED with no bleaching or growth stunting.


PW

 

[ridetheducati]

Double post.

 

[ridetheducati]

I'm not sure where the "double" ever came from, but certainly not Apogee.

I cannot understand it either. More disinformation.

 

[sahin]

From Apogee..
http://www.apogeeinstruments.com/light-intensity-measurements-for-light-emitting-diodes-leds/
also
http://www.apogeeinstruments.com/content/Quantum Sensors-LEDs.pdf

I'm not sure where the "double" ever came from, but certainly not Apogee.

I've found using Apogees error correction works relatively well as I did with my meter when I moved from MH/T5's to LED with no bleaching or growth stunting.


PW

I cannot understand it either. More disinformation.

+1 to both. I've conversed with Jacob Bingham (Applications Engineer at Apogee) many times over the use of their quantum meter and found the error correction works well.

Besides, Dana Riddle has directly compared the Apogee to the Li-Cor and the measurements are not far off. In fact the Apogee measures very closely when in Sun Calibration mode to the Li-Cor. Only when measuring a very GREEN light source does the Apogee overread by a fair bit. By and large its perfect for hobbyist purposes.

 

[Tete]

I read some of those posts and it did clarify it for me.

Doh, typo! I meant that it "didn't" clarify it for me.