Is it about time to change the T5 light bulbs? Par meter readings

[thompsontwins]

bulbs are cheaper as well not much difference between 39 and 80 deffinately the 39 watt is not 1/2 the price of the 80watt

[rhoptowit]

got new bulbs but have been slacking about getting new PAR readings. i took a quick reading and wow what difference new bulbs make in PAR numbers. so far the bulbs have been running since sept 16th from 1pm to 11pm daily.

mid tank was from 500-550, couple inches above the sand bed was 350-400. didnt bother to take anymore since im lazy.

[kangym]

rhoptowit, did you replace new bulbs on both 24W and 39W ATI PMs? The same bulb combination? Pictures please.

[kangym]

Time for par reading. 10x54W ATI PM 4 months old lamps.
Fixture still at same 9 in. above water level. Nothing change. Side by side comparison with 2 weeks new lamps.

2 weeks old lamps


4 months old lamps

[kangym]

Plan to lower the fixture down once the center water level par reading drops under 900. Maybe another month or two. The par readings still look very good at 4 months.
Here is clean FTS

[luvreefs23]

I got a 10x80 ati pm over my 250, ordered an apogee par meter and will be here friday. Ill try to get some random readings from my fixture. my bulb layout (from memory) is

ati blue plus
ati blue plus
kz fiji purple
ge 6500 daylight
giesemann actinic plus
ati blue plus
ati blue special
kz fiji purple
ati blue plus
giesemann actinic plus

Ill confirm this when i know some par numbers.

Dennis

[rhoptowit]

kangym: just changed the bulbs on my 36". bulb combo now is....

ati blue plus
ati blue plus
uvl 25/75
ge 6500k
ati blue plus
ati blue plus

the 24" is the same. ill get pics up soon.

[kangym]

Originally Posted by luvreefs23

I got a 10x80 ati pm over my 250, ordered an apogee par meter and will be here friday. Ill try to get some random readings from my fixture. my bulb layout (from memory) is

ati blue plus
ati blue plus
kz fiji purple
ge 6500 daylight
giesemann actinic plus
ati blue plus
ati blue special
kz fiji purple
ati blue plus
giesemann actinic plus

Ill confirm this when i know some par numbers.

Dennis

It will be great if we could see another 80W T5 par reading. Also a good opportunity to find out the difference between 8 bulbs and 10 bulbs.
I found the par reduced almost 5 to 10% only running 8 bulbs of my 10x54W PM.

[stealle]

It seems like it would be a good idea to change half of the bulbs about every ~4 1/2 months instead of all of them every ~9 months. For example, on an 8 bulb unit, replace 2 of the blueish bulbs and 2 whitish bulbs, then 4 months later replace the 4 bulbs. You would still get 9 months out of the bulbs

Your system would have less fluctuations in PAR and spectrum. Any thoughts on that?

[kangym]

I think you got the point. I can regain the par by lowering down the light fixture after 5 to 6 months. But I can not regain the spectrum unless replace with new lamps.
Base on my observation, I still have pretty good par reading with 10 months old lamps, but the growth slows down, and it is hard to bring the color out. So spectrum is another big factor. No wonder those European reefers like to change the lamps every 6 months.

[LISound]

Any par readings on the sunpower? Can't seem to find any. I'm looking at the 24in for a 30" long tank, 18wide, and 21 high.
It's either that or a DIY retro with active cooling. for the cost, I can get a sunpower and not have to worry about weather or not I'm cooling the bulbs well enough in my DIY setup.

[kangym]

Just found something very interesting. The ATI PM was accidently running 2 days without fans on. I checked the par without fan, the highest reading at water level is only 700. Overall, the par readings drop 150 to 200 without fan. I turn the fan back on and raise the speed setting from 7.5v to 9v. Check the par again, the readings are even higher than last month. So cooler lamp produces more par.

[kangym]

Par reading for 5 months old T5 lamps. After raise the fan speed, the par reading are higher everywhere in the tank.
ATI 10x54W PM, hanging at 9 in. above water level. Fan speed set at 9v.

[moo0o]

wow cool. These numbers are about the same as they were and in some cases higher than they were a month ago.

[mdemuth]

I guess fans do make a difference with T5's

[snaza]

What voltage were you running the fans at before?

[kangym]

The instruction recommends 4.5v. Grim reefer suggest 9v. I used to run my ATI PM at 9v. But when I checked my setting, it was set at 7.5v.
Yes, if you are running T5 fixture with active cooling fan, please dial the fan speed up to 9v or higher. It makes a big difference.

[snaza]

My 10 bulb PM arrives in 2 weeks. So i'll do some tests with different fan speed.

[moo0o]

Originally Posted by arod2051

I tried my link above and it didn't exactly put the relevant post. Here is the actual post.

ATI Powermodule Test

In my quest to extract as much efficiency from my equipment and the fact that I was confused on some of the knobs I can turn on my ATI 8x24W powermodule I ran a few tests.

This test tests two things. The first is the bulb orientation. I wasn't sure which way to orient the T5 bulb. There are two ways to orient the bulb. The first is with the label near the exhaust port of the fixture and the second orientation is with the bulb label near the cord. The second test finds which fan voltage provides the most efficiency. The recommendation is 4.5V but some users were using the fixture at 7.5V. There is an intermediate step of 6.0V.

To be clear, when I mention efficiency, I am really finding which setting provides the most PAR. I am using an Apogee QMSS-EE PAR meter to take my measurements.

This table shows the actual PAR measured.


Although the nominal data is interesting and I'll touch on it later in this post. I wanted to find out how each variable affects the PAR rating. Since I took PAR measurements at different depths I had to normalize out the depth of the measurement. This is why the nominal data is interesting but could not be used for this test. I took the 4.5V and exhaust-side orientation as the default measurement. Any subsequent measurement afterward is noted as a gain or loss of PAR in percentage.

This table shows the difference from the 4.5V fan-voltage and exhaust-side orientation.


I then went one step further and ran a linear regression to see how each variable affects the growth number. I came up with the following regression equation.

Par Growth = -2.7% + .68%*[Fan Voltage] + 2.5%*[Bulb Orientation]

I'll explain this in a bit more detail. For the easy part, it is clear that placing the bulbs with the cool-spot (label) near the plug side of the fixture resulted in a 2.5% increase in PAR. The fan voltage is a bit more complicated. This is where I used the nominal data to make an informed decision. The data show that increasing from 4.5V to 6.0V increased the PAR in most cases, but increasing from 6.0V to 7.5V was not as dramatic and also had more areas where the PAR decreased. This accounts for the only slightly positive PAR growth of 0.68% with each voltage increased.

For my tank, I am going to keep the bulbs with the label at the plug-side and leave the fan voltage at 6.0V to keep the fan noise down and PAR up.

As a quick note, each PAR measurement was extremely variable. So the regression did have a fairly weak R-squared value of 30%. This means that of the PAR growth, about 30% can be explained by the two variables given. I think my measurements with the PAR meter were so dependent on exact placement a lot of the weak R-squared comes from that and other tank variables. Still the regression had a really low F-significance, so I am confident the data show that the two variables do have some affect on the PAR. 99.98% positive to be exact.

Kangym, have you looked at this post yet and are your bulbs arranged in the way he suggests? Im curious if your numbers change if you had to rearrange your bulbs according to how he did it.

[kangym]

Thanks for the information MooOo. It answers many of my questions. Do you have the link of the original post?

When I checked the par of Thompsontwins' tank, he mentioned the par readings are higher at plug side. But my is opposite, the par readings are higher at exhausted side. So it must be the orientation of the bulb. I will check the label orientation tomorrow at work.

In arod2051's experiment, no 9v setting has been tested. In my par readings, 9v produces more par than 7.5v, even with one month lag. I will try to duplicate arod2051's protocol and test on 9v setting.

[kangym]

Originally Posted by snaza

My 10 bulb PM arrives in 2 weeks. So i'll do some tests with different fan speed.

Thanks Snaza, can't wait to see your result. We need more people to chime in. What size of PM you will get?

[snaza]

Same as yours 10x54w

[moo0o]

http://www.reefcentral.com/forums/sh...5#post15766775



and yep no problem, i am just as interested in these t5s and their par numbers as you are. Btw, its pretty much winter now, my house has been ~70 degrees where as a month ago it would be ~80degrees. I would think this would have a huge effect how on well those fans cool your t5s. Have your room temps changed in the past month or is fan speed still the only variable?

in the future, the link for any of these quotes can be found by clicking on the blue arrow thingy right of their name where it says Originally Posted by name insert arrow here

[kangym]

Thanks for the link mooOo.
I checked the T5 lamps this morning, all lamps have label on plug side. But I still get higher par readings on the exhausted side.
The room temperature is pretty stable in my office during the day. It drops about 5 to 7 degree at night compares to last month. I run T5 lighting only during the day, so the room temperature shift may not be a variable in my case.
I am still in shock to know losing 200 par without cooling fan. Anyone ever try 12v fan speed?

[sanababit]

Originally Posted by kangym

I am still in shock to know losing 200 par without cooling fan. Anyone ever try 12v fan speed?

i have an ATI PM 6x54w, i tried it at 12v, but the noise was killing me, so it went back to 9v, i will try to get a par meter this weekend and post results, my lamps are 2 months old

sana