Too Much Air Movement Across Lights?

[Goldstripe]

I am wondering if it's possible to have too much air moving across my MH fixtures as to prevent them from getting up to temperature and/or PAR value. I'm running ROIII's with Reeflux DE 10k's on IceCap 250 eballasts. Recently I've been noticing some STN on some of my SPS and one of my oldest LPS's (trumpet coral). Adding a blower type fan is 1 of the things I've changed lately in the last month or so. It's on a Ranco temp controller so it only comes on when the tank temp reaches 77 +1 degrees. The only other thing I've changed is to remove 2 of my Actinic+ T5 bulbs out of the array of lights. This leaves me with 2 true actinic and the 2 x 250 10k bulbs already mentioned. Almost forgot, around the same timeframe, I also changed the temp control to come on at 78 instead of 80, thereby reducing my temperature and of course increasing my evaporation. Any ideas?

Today I moved the blower fan to circulate air in the sump area and also put the actinic + bulbs back on.

I posted this in the lighting section several days ago but didn't get any responses so I figured I'd try here

[Goldstripe]

One other thing is I've tested my PO4 with a colorimeter and came out at .04 which I know is high. I'm working on getting that down with water changes / and picking up a phospate reactor

[fish.freak]

I dont think too much air movement would affect par.

[Goldstripe]

maybe not the air movement itself but do you think if the bulbs were kept too cool they wouldn't get to the right color temp?

[fish.freak]

no, the bulb is sealed and the filament is hot trust me.
do you see a difference with the fan on and off?

[jamessp01]

what are your other parameters? is the STN starting at the bottom?

[ANGRY JOHN]

the temprature of the bulb is critical to its function. most of the time we under cool it and that shortens the life and may change the color. if you have a way to measure surface temprature it will be an indication of where you are and if that is the problem. they sell guns for checking air conditioners and things like that. you might pick one up and see what you find.....

[wharyat]

Yes, it is possible to cool the bulbs too much to where light ouput is affected. MH, as with all other forms of lighting, have an optimum operating temp.

I woudn't attribute the STN to light output tho as the output would only be down around 5%.

[fish.freak]

I stand corrected...

[DarthOcellaris]

i know I've read the same thing about heat affecting PAR. I wonder exactly how much it really affects it though.

I also agree that your STN wasnt caused by that