Kessil 360W or WE PAR

[VR28man]

Hey all,

I borrowed my club's par meter, and measured PAR of my (newish) A160WE and (several years old) A360, four inches below the lenses (running at about 100% intensity and 50% color). I got ~1400 PAR for the A160WE and ~2900 PAR for the A360W. (since the WE is supposed to be 30% more efficient, a hypothetical 160W would be ~1100PAR)

Would someone mind posting any results they may have for a newish A360W and/or A360WE?

As an aside, I was disappointed. I thought I'd have good coverage, but the top 1/3 of (where I keep my bright light acros and pocilloporas) barely get 250PAR, with the cover off. I got around 125PAR, under the light, at the bottom of the 16" tank. [ETA: I will have to play around with the configuration. They are about 8" from the water surface through a cover. 30X11X18 tank]

[ETA: did a more careful measurement at 4", and revised numbers]

 

[Crabs McJones]

How far off the waters surface is the kessil mounted and in what size tank?

 

[mcarroll]

I would mount them lower to the tank for optimal internal reflection inside the tank.

This type of light does make up for lower peak numbers (aka better spread) to a respectable degree by causing lots of internal light reflection inside the tank....side-lighting, in essence.

Mounted too high you miss out on a percentage of this...the higher, the more you lose.

 

[mcarroll]

You can also see that with the lower mounting, you create a zone at the surface of much higher intensity as well due to the overlap of the two light cones.

 

[jda]

You are seeing why most people with Kessils use one with every linear foot and/or add 4x T5s. They are not powerhouses in any stretch of the imagination.

I would not sweat the measurements 4" from the lights in the open air. This is probably a difference in how the meter reads the stuff (cosine correction, etc.). Which meter did you use? They are not all the same nor will the get the same numbers in readings.

 

[madweazl]

Most people dont take advantage of what the A360s do well and mount them high off the water when going the other direction would be a better choice; their spread and color blending is far superior to most LEDS and can be placed very low with good results.

You can find some PAR results here

 

[VR28man]

Thanks, all, I'll read all this, think about it, and play with the Kessil arrangements.

Per madweazel's post, the meter is "our local clubs Apogee MQ-500 with full spectrum sensor", assuming we've kept the same meter.

 

[mcarroll]

I think you're at a slight disadvantage with the very-narrow tank....that calls for ultra-low monting if you're going to avoid spilling A LOT of light over the front and back of the tank – wasting PAR.

But by the math, to fit it all into 11", you'll need to mount the lights 2" from the water. ;Drowning

If you go with the narrow-lens A360's (which are 90º, right?), you should be able to get away with a more-acceptable mounting height of around 5-6 inches.

Kessil's ligting guide has a 40 Gallon that is somewhat close to your dimensions and they say 2-3 for that. 2 should be fine for yours, but I bet you wouldn't regret 3 either.

http://www.kessil.com/aquarium/getting.php

 

[jda]

Did you apply the 1.32 immersion factor to your measurements? The MQ-500 does not have it already like the MQ-510 does for underwater use. If not, your readings are low.

It is really important to explain which PAR meter was used when tying to compare apples to fettuccini noodles.

 

[VR28man]

Did you apply the 1.32 immersion factor to your measurements? The MQ-500 does not have it already like the MQ-510 does for underwater use. If not, your readings are low.

It is really important to explain which PAR meter was used when tying to compare apples to fettuccini noodles.

No, not yet. Again, very new to this, but thanks.

 

[ikolbaba06]

I was also surprised by the output of the a360 over my frag tank. I much prefer my ap700s but lowering the a360s help to push the par up higher.

 

[hart24601]

I personally think more people should be using the narrow version especially if they have a tank that is 24" deep or more or if higher PAR on the bottom of the tank is important to them.