Ati sunpower output

[MichaelW]

I mentioned this in a different thread but was suggested i start a new one to not de-rail the other one.

Anyway the situation is this.
I have a 8x39watt ati sunpower over my frag tank. Bulbs are 6blue plus, 1 purple plus, one coral plus. Height of fixture i think is about 12 inches off water line. Tank only has about 8-9 inches of water in. I believe the fans are working properly. now the problem is i am testing par with an apogee mq500 and i am getting much lower par numbers than expected. I see some people posting numbers like 700 just under surface and 250 on sand beds of 20+ inch deep tanks. Well i get like 350 an inch or 2 under the surface. I know bulb choice will play a role but even with that much blue+ bulbs i would expect more.
Where do i start looking for reasons why i am not getting the output i expected? I dont believe i even get that high numbers (800 etc) a few inches under the fixture in air.

It is always possible 2 that is the par meter is faulty and the fixture is fine.

[codydemmel4]

how old are the bulbs? are the reflectors all clean and shiny?

[Unanonymous]

Are you running carbon and is your water very clear, or slightly cloudy? Water clarity can have a big effect


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[MichaelW]

Its all fairly new 3-4 months. Everything is clean. Even tried removing the plastic guard to take a couple readings to see if that was effecting anything....it wasn't.

Yes i had thought about is it possible my water isnt that clear.... But to me it looks clear. Clearee than other tanks i have seen. But that is why i took some readings in air just above the water and they still were not as high as some peoples in water.

[rtparty]

What are your fan settings?

What is the temperature of the air exiting the fixture? This is easy to test. Let the fixture run for an hour or 2 and then put a thermometer on the end where the air exits. What does it read?

Are the bulbs properly inserted into the fixture? Meaning the label end is below the holes in the fixture.

Are your fans pulling air in or pushing air out?

Finally, wasn't the new Apogee the meter that BRS found to be faulty and not read properly?

[bshow24]

I can't totally help, but I can tell you 6 inches below the water my retrofit kit alone (2 bulbs) puts out 300+ par. Either the PAR meter is incorrect, or something else is going on with those lights. Start doing what rtparty has stated and see if you can find anything.

[jda]

A few more coral plus will bring this up. PAR is just a number that does not mean much in actual life. You are most likely fine with what you have, so don't worry about it.

[koral_lover]

numbers seem pretty accurate to me....i get about the same measurements when my fixture is 12 inches off the top (8X24w)...that is pretty high up - I run mine 6-7 inches awl....also I find if i run more white bulbs my apogee mq 210 (i think?) measures higher par...your par meter could just be under measuring the blue spectrum...re-watch the brs video and see what they find about your particular meter, I can't remember

[koral_lover]

also - its been a while, but I believe reading 5-7 years back, that the longer ATI fixtures put out quite a bit more PAR....so if your comparing your numbers to someone else, length of bulb may be important...

[rtparty]

also - its been a while, but I believe reading 5-7 years back, that the longer ATI fixtures put out quite a bit more PAR....so if your comparing your numbers to someone else, length of bulb may be important...
Length of bulb has almost zero impact on PAR. The only length that tends to be about 5% higher is the 60".

T5s are not like halides or LEDs in that more wattage can lead to higher PAR. It just means there is a larger area where maximum PAR is reached.

[MichaelW]

So just measured to make sure. The lights are actually 10 inches above water line. All bulbs are in the correct way around. I havnt measured the temp of air leaving the fixture as cant find a thermometer right now. Under the center of the fixture about 10 inches below at the water surface but in air, so no chance of it being murky water, i get around 480. Just doesnt seem enough when people get much higher under water.
From what i can tell the fans are pulling air in through thefixture and not out, but its not like they suck my hand to them. I turned up thevoltage from 9 to 12 just to see.. Itmade them louder.
I dont think the mq500 wastested by brs most likely they used the newer one the mq510 or the older one that most people seem to have. Either way it just doesnt seem correct from what i haveheard aboutthese lights. How can you check you par meter reads atleast semi accuratly?

[MichaelW]

A few more coral plus will bring this up. PAR is just a number that does not mean much in actual life. You are most likely fine with what you have, so don't worry about it.

Im not worried aboutthe number so much as concerned there might be something faulty with my light fixture

[MichaelW]

I think the fixture is possibly running 2 hot. I stuck a glass thermometer begween the splash guard and the bulbs and it read like over 110 degrees. Basically as high as the thermometer went now question is why is it so high. Fixture is not enclosed. Is in the garage where it is colderthan the house this time of yearanyway. Fans are spinning.

[rtparty]

110 leaving the fixture isn't bad. The cold spot should be around 95°F so add in the length and 105 or so is normal.

I'm wondering if your meter is wrong. I have no idea how you would check that

[MichaelW]

110 leaving the fixture isn't bad. The cold spot should be around 95°F so add in the length and 105 or so is normal.

I'm wondering if your meter is wrong. I have no idea how you would check that

Where is the "cold spot"

[MichaelW]

This is how i measured. Just stuck it in the end between the splash guard. Now the temp may have been higher, as you can see, it was the max for the thermometer.

http://i1148.photobucket.com/albums/o578/wenham09/Tank/20170323_191823_HDR-01_zpsgxaegm9x.jpeg (http://s1148.photobucket.com/user/wenham09/media/Tank/20170323_191823_HDR-01_zpsgxaegm9x.jpeg.html)

[rtparty]

Where is the "cold spot"
The label end of the bulb.

[MichaelW]

Ah so the other end with the holes above each bulb? I will pull the splash guard back a bit and test there tomorrow. My goal for this frag tank was an area up high getting 500ish par and then lower areas still getting around 300 ...if my readings are acurate doesnt look like i will get that.

[CoralNutter]

yeah that definitely sounds low my ati dimmable 48" with 2 actinic 4 blue+ 1 coralplus and 1 purple plus i am now about 11 inches off the water since i moved it up and i get about 550 an inch under the water and 270ish meter laying flat on the sand 22" down

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[Big E]

I haven't worked with the 500, but if the meter is set up the same as the 200 make sure you have the setting on "Electric". Sun mode will give lower readings.

You aren't going to get the same par numbers as someone with 48" 54w bulbs. Make sure you're comparing apples to apples.

Coral+. Blue+ and AB special will give you the highest par numbers.

The fixture is probably too high as well.............move it down some so you have about 350 at mid level of your tank.

[MichaelW]

I haven't worked with the 500, but if the meter is set up the same as the 200 make sure you have the setting on "Electric". Sun mode will give lower readings.

You aren't going to get the same par numbers as someone with 48" 54w bulbs. Make sure you're comparing apples to apples.

Coral+. Blue+ and AB special will give you the highest par numbers.

The fixture is probably too high as well.............move it down some so you have about 350 at mid level of your tank.

The 500 doesnt have option to choose between sun and electric.

I was under the impression with t5 the longer bulbs just cover more area to give light not necessarily give off more light right under the fixture?
I see comments like above where they have the fixture higher than mine (mine is 10 inches) with actinic bulbs that i dont have but getting 550 par.
It could be the meter and not the fixture. I also got lower than expected when testing under my leds.

[rhinonm]

So with the MQ-500 you have to multiply each reading by 1.32. The new meter does read led spectrums better but doesn't measure under water as well as the old 200.

google: Apogee Releases Calculator for Underwater PAR Measurement

[rtparty]

I was under the impression with t5 the longer bulbs just cover more area to give light not necessarily give off more light right under the fixture?

This is correct. Higher wattage (read longer) bulbs do NOT produce more PAR. At least not enough that it matters.

Here are some calculations:

24" = ~1w per inch
36" = ~1.08w per inch
48" = ~1.125w per inch
60" = ~1.33w per inch

The "extra" wattage is mostly wasted and not turned into usable light. The 60" bulbs do tend to have slightly higher PAR per inch but it is negligible for our use.

So while it isn't apples to apples to look at the PAR from a 48" ATI and wonder why a 36" doesn't have the same numbers, it is usually close enough for our purposes. What shouldn't be compared is two different brands of lights UNLESS you are comparing them against each other. For example, fixture A puts out 20% more PAR than fixture B when using the same wattage.

[CoralNutter]

I have a funny suspicion that is has to do with fan speed because the dimmable ATI has an auto configuring fan controller that keeps it running optimal speed. Have you tried tuning your fan?

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[Big E]

This is correct. Higher wattage (read longer) bulbs do NOT produce more PAR. At least not enough that it matters.

Here are some calculations:

24" = ~1w per inch
36" = ~1.08w per inch
48" = ~1.125w per inch
60" = ~1.33w per inch

The "extra" wattage is mostly wasted and not turned into usable light. The 60" bulbs do tend to have slightly higher PAR per inch but it is negligible for our use.

So while it isn't apples to apples to look at the PAR from a 48" ATI and wonder why a 36" doesn't have the same numbers, it is usually close enough for our purposes. What shouldn't be compared is two different brands of lights UNLESS you are comparing them against each other. For example, fixture A puts out 20% more PAR than fixture B when using the same wattage.

I stand corrected...........I just remember when I tested my friends tank with 24" bulbs he was pulling considerably less par than my 48" bulbs. It could very well have been other factors involved.

I would agree the other factors like ballasts, cooling, bulb types,ect. are important considerations.

[Piper27]

I have a funny suspicion that is has to do with fan speed because the dimmable ATI has an auto configuring fan controller that keeps it running optimal speed. Have you tried tuning your fan?

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How do you tune a fan on the dimable units?

[rtparty]

I stand corrected...........I just remember when I tested my friends tank with 24" bulbs he was pulling considerably less par than my 48" bulbs. It could very well have been other factors involved.

I would agree the other factors like ballasts, cooling, bulb types,ect. are important considerations.
Ballasts, cooling and reflectors play the biggest role in how much PAR a bulb will produce. Assuming the bulb(s) is a good bulb to begin with.

You could also take the same set of bulbs and put them in 5 different, but same brand, fixtures and you'll have differing numbers. But does it really matter if one fixture reads 300 and another is 310? I've always chalked that up to the acceptable range of error.

[rtparty]

How do you tune a fan on the dimable units?
In the controller you can set fan speed. I believe there are YouTube videos about it from ATI

[drawman]

Anecdotally my 24" x 4 bulb powermodule had way less PAR than I had expected when I was doing measurements over my frag tank while running 2 C+ B+ P+ bulbs. I run my fans on the slow side as they make a ton of noise when I ramp them up :/.

[MichaelW]

Im starting to think maybe it is actually the par meter.
I have a 2 bulb 80 watt hamilton fixture running 1 coral plus and 1 blue plus and about 8 inches under that (in air) was only like 300 or so if i remember correctly. So this also just doesnt seem enough... Granted they are not a "cooled" fixture bht it is in an open hood with fans creating airflow.

The other thing i am thinking (no idea if this could happen or not) it could be is possibly my house electrical is not providing the correct amout of power?

[Potatohead]

105 - 110 degrees of air temp leaving the fixture is pretty much bang on. FWIW I have the 24x8 as well and mine leaves at 108 on 9v setting, room temp is usually 69-70. I bet the meter is wrong.