Quick dumb T5 par/coverage question

[Scorpius]

Lets say if I have a 36in 4 bulb t5 unit over my 36in wide tank and I get 250 par under the light and I decide to go to a 36in 6 or 8 bulb t5 unit with the same bulbs would I increase the par over 250 or would I just have more coverage of 250 par throughout the tank?

Thank you in advance here's a cookie for your time,

 

[Crabs McJones]

Lets say if I have a 36in 4 bulb t5 unit over my 36in wide tank and I get 250 par under the light and I decide to go to a 36in 6 or 8 bulb t5 unit with the same bulbs would I increase the par over 250 or would I just have more coverage of 250 par throughout the tank?

Thank you in advance here's a cookie for your time,

I would believe that by adding more bulbs, you would increase the par

 

[Scorpius]

I would believe that by adding more bulbs, you would increase the par

I don't see how it would if you're running the same bulbs and length. I'm an idiot though when it comes to stuff like this.

 

[Crabs McJones]

I don't see how it would if you're running the same bulbs and length. I'm an idiot though when it comes to stuff like this.

I'm thinking then that it doesn't increase the par (not much a substantial amount), but increases the coverage of that par.

 

[mch1984]

Just an opinion and not a professional one. I would think you would increase par some, but not let say double the par for double the bulbs. I think you will get better coverage but also some increase in par. the light coverage is going to intersect with each other and if you add more intersections the par would increase. Just my .02 on that.

 

[jda]

...so we are talking 4 bulb to 8? If so, then the answer is C... both. On the ends, you will still have 250 because they are just like the ends now. In the middle, you will have more because there are more bulbs on either end. I do not know if you can 2x the output, but it is more.

You can google PAR readings for ATI T5 PAR readings and BRS has done some studies, but their results have been low due to a miscalculation in the LiCOR that they use.

 

[Scorpius]

Ok. Thanks guys

 

[madweazl]

If you double the lights, I don't see how you wont double the PAR unless the distance they're separated by doesn't overlap.

 

[Scorpius]

How would it double par? If a t5 puts out say 200 par per bulb how could 8 bulbs total 1600 par? That doesn't make sense. Isn't it still just 200 par?

 

[Scorpius]

Okay. Lets say I have two 500 lumen flashlights. If I put the beam of one on top of the other don't I still have 500 lumens of light? I just don't magically get 1000 lumens do I?

 

[Potatohead]

Rule of thumb is ~160 par per lamp about ten inches down from the center of the fixture. I’m sure it’s not an exact science but you do gain more par with more bulbs because they overlap quite substantially, especially with good reflectors.

 

[trido]

The lights spread coverage over each other and increase the par. The same concept of LEDs. One emits x amount of intensity, but many multiplies the intensity.

 

[oreo54]

Okay. Lets say I have two 500 lumen flashlights. If I put the beam of one on top of the other don't I still have 500 lumens of light? I just don't magically get 1000 lumens do I?

Funny discussion...
Lets put this another way.. Say you have a flashlight that runs at 1 Watt and produces 500 lumens.. (so 500 lumens per watt)
Say you double the power to the flashlight running it at 2 watts.. You will now produce 1000 lumens (500L/w X 2watts = 1000L)

Take 2 500 lumen 1 W flashlights and magically superimpose them. Now you have 2X 500L = 1000 lumens
Lumens are arealess so keep that in mind but now for a 3d world..

no magic involved....

now picture 4 or 6 or 8 tubes w/ larger spread and see how each will overlap (adding PAR)..
will it be 2 or 3x as much.. Depends where you are...
Push the 3 on the right together till all are adding...

 

[EW_Fish]

Funny discussion...
Lets put this another way.. Say you have a flashlight that runs at 1 Watt and produces 500 lumens.. (so 500 lumens per watt)
Say you double the power to the flashlight running it at 2 watts.. You will now produce 1000 lumens (500L/w X 2watts = 1000L)

Take 2 500 lumen 1 W flashlights and magically superimpose them. Now you have 2X 500L = 1000 lumens
Lumens are arealess so keep that in mind but now for a 3d world..

no magic involved....

now picture 4 or 6 or 8 tubes w/ larger spread and see how each will overlap (adding PAR)..
will it be 2 or 3x as much.. Depends where you are...
Push the 3 on the right together till all are adding...

This is perfect I was about to draw up a graph/picture but this is exactly what I was about to draw up

 

[Scorpius]

So overlapping light increases intensity.