CurrentUSA T5HO Fixture PAR Readings

[Ace25]

Short answer.. around 440 PAR.. the proof...

Bulbs are 2x Philips 24w T5HO 3000k


Fixture is a CurrentUSA Nova Extreme


Sensor is placed 2" under fixture with black background.


Highest stable PAR reading was 500. It got up to 650 on warm up but then dropped down to 500 before it stabilized after 10 minutes. Average reading I would say is around 440.


Youtube Video moving the sensor around to show average PAR from center to edges.
http://www.youtube.com/watch?v=5azoSZwaa9o

[Ace25]

I thought I would have gotten at least 1 response to this. I would have thought that would be good information for all since we have a # to use as a guideline when choosing other lighting types (CFL/LED/etc).

[salty joe]

You will get at least one reply! Thanks for that bit of info. I'm also very interested in your LED work. I want to know what will grow the most algae with the fewest watts. Thanks for posting your work!

[johnarky]

Hey Jeremy (ace)... Do you have any other PAR readings to compare this to? For example... I'd be interested in what a 42 watt spiral CFL bulb is putting out (also a 23 watt).
Curious how the lighting on these diy scrubbers compares to the SM100.

[Ace25]

Thanks for the replies! I was hoping someone would ask for something else PAR related. Just keep in mind the spread difference between T5HO and CFL. I was only testing directly under, on T5, it is the same PAR across the entire width of the screen, on CFLs you get circle patterns of different light intensities instead of bars.

23w CFL Flood Light 3500k / Opaque Cover = 390 PAR 2" from light
26w CFL Flood Light 3000k / Clear Diamond cover = 390 PAR 2" from light (I was surprised it was identical to the 23w)
26w CFL CurlyQ 2700k = 700 PAR 2" from light (6" Reflector)
42w CFL CurlyQ 2700k = 1490 PAR 2" from light (6" Reflector)
68w CFL CurlyQ 2700k = 1350 PAR 2" from light (no reflector fits this beast of a bulb so most of the light is lost/wasted out the side) Bought this bulb at Home Depot, 300w equiv bulb.

Ghetto test rig showing PAR of the first bulb on the list above. If anyone wants a specific picture of a PAR reading just ask.. if you want a specific distance because that is how your ATS is setup, again, just ask so you can have real numbers for your setup.

[SantaMonica]

I think for CFL's, using 4" is probably more common.

Would be neat to see the dropoff from the center to the edges, of CFL's with and without reflectors. And for T5HO's too, in the perpendicular direction.

[Ace25]

Sounds good SM, I will re-run the tests this evening with a 4" gap instead of 2" and post the readings from that distance. Do you want youtube videos showing the "spread" to show the range in PAR on CFL and T5HO? The video in the first post kind of shows the T5HO spread but I can do it better and just pull the sensor cross ways to show it instead of moving the sensor all around. I can do the CFL with/without reflectors but the T5s would be a little difficult seeing the reflector is inside the fixture.

[Floyd R Turbo]

I totally missed your thread, must've been a busy day that day. Thanks for the info

[Ace25]

Some more readings, this time with a better rig to hold the lights and very precise measurements. Tip of each bulb to tip of sensor was exactly 4".

26w 3000k CFL Floodlight, Clear cover/diamond pattern. Measurements at highest point in center, then sensor moved exactly 1" increments from center.
Center = 300 PAR
1" = 260 PAR
2" = 160 PAR
3" = 100 PAR
4" = 60 PAR
5" = 40 PAR

26w 2700k CFL Spiral with 6" reflector.
Center = 330 PAR
1" = 265 PAR
2" = 210 PAR
3" = 140 PAR
4" = 90 PAR
5" = 50 PAR

26w 2700k CFL Spiral with NO reflector
Center = 115 PAR
1" = 100 PAR
2" = 85 PAR
3" = 60 PAR
4" = 40 PAR
5" = 28 PAR

That is all I have for tonight.. I will do the T5's and 42w CFLs tomorrow.

[Floyd R Turbo]

I take it these measurements are with the lamp pointing at the sensor. Since some people hang the lamps and put a side reflector on it, what about doing that with/without? You might need to include readings at 1" increments in a grid pattern for that.