Seneye PAR readings vary so greatly

[jason2459]

I guess it helps I have LEDs completely plastered over my canopy running at relatively low percentage and some T5s right down the middle. I seem to have like 0 hot spots.


@ItsAName what kind of lighting do you have and how is it setup? Height from water, how many fixtures, etc.?

I'd be curious if it's just reading like it should and finding the light source is very narrow creating heavy hot spots. LED, narrow lens, high intensity, single fixture, etc.

 

[jason2459]

Oh, and I want to know the exact angle so a single quick flashlight swipe over top just wont do... lol

But I was thinking a narrow beam LED flashlight as the source after I posted that post. Keeping the flashlight mounted overtop still and variable heights and rigging a protractor with the sensor

 

[ItsAName]

I have two Radion XR15w G4 PRO. The tank is 4 feet long, and they are each placed center at 1 foot and 3 foot. The tank is 18 inches wide and it's dead center. I'm using ecotech's mounts so they are 9 inches above the water. Here's a pic if it helps

How did you rig a protractor to it?

 

[jason2459]

Oh yeah, I can see that creating two big hotspots. Par dropping a 100 on angle depending on location I would not be surprised.

I haven't rigged up the protractor yet. Still going back and forth in my head on the details. Probably be a little bit before I do it as other things are going on right now.

 

[Tristan]

Do you have any rippling when you measure the par? When the water ripples, it acts as a lense and focuses the light

 

[jason2459]

Do you have any rippling when you measure the par? When the water ripples, it acts as a lense and focuses the light

I have a lot of rippling. I found no negligible difference with and with out pumps on.

 

[jason2459]

Here's a video for reference and I actually have another gyre now horizontal on my back left wall.

 

[myboyblu]

oops wrong thread

 

[HolisticBear]

The general consensus seems to be a) hold steady for longish time b) ignore the lows c) take a average of the highest readings at whatever angle gives the highest light?

I spent about an hour measuring yesterday and trying to keep the sensor in the same spot, but rotating the sensor 90 degrees (still pointing at same angle to the light) the PAR changes drastically, like 50%. I should take the higher value it seems.

The other big thing I didn't see mentioned is what happens when you hold the unit against the glass. This keeps it stable and the sensor is probably 1/4" off the actual glass. However my PAR readings are much much higher than if I moved the sensor a half-inch off. I assume this is related to glass reflecting the light, but is the reading more or less accurate (actual hotspot or sensor side-effect?). Numbers 50+% different, maybe 70% different, moving it a 1/4" off the glass.

Is right up against the glass a real hotspot in tanks? Most things aren't within that 0.5 inch range, but maybe there is a 0.5 inch hotspot along all the glass in our tanks? Or maybe the reflections confuse the sensor.

Next time around I'll keep it an inch off the glass and just move the sensor in all directions to get the MAX PAR.

 

[jason2459]

I hold the seneye or apogee sensor against something like the sand bottom, rock, or glass to keep them steady. Both drastically change based on movement, angle, fish swimming by, etc

If it increases up against the glass then it's probably accurate. Either reflected light or coming from outside the tank like sunlight. Reflected light most likely.

For me my led lights are angled in and T5s right down the center. I have my lowest par readings against the glass.

 

[HolisticBear]

For me my led lights are angled in and T5s right down the center. I have my lowest par readings against the glass.

Thank you.

Given I'm running my LEDs a little high, with lots of spill, the reflected light makes sense.

 

[saltyfilmfolks]

Thank you.

Given I'm running my LEDs a little high, with lots of spill, the reflected light makes sense.

You'll get less shading that way.

 

[jason2459]

You'll get less shading that way.

All depends on the angle.

 

[saltyfilmfolks]

All depends on the angle.

And where stuff is in the tank.