Rethinking this T5 thing

[The Grim Reefer]

Stop by and gawk at iwan's tank if you haven't already done so.

The Mother of All T5 Tanks (http://archive.reefcentral.com/forums/showthread.php?s=&threadid=700454&perpage=25&pagenumber=1)

He is changing the T5 lamps every 6 to 8 months. His experience with growth stagnation after about 8 months backs up what I've been told about the spectrum shift in lamps at 6 months or so. He does have a long photo period and a huge amount of light hungry corals in a large tank but it is hard to dispute his methods based on the results.

I think the T5's need to be changed every year at the maximum if you want consistant performance. I know my 14 month old lamps still have plenty of PAR output but it seems obvious that the decrease of certain spectrums will affect coral growth. Perhaps the sun and daylight lamps will last longer but why take a chance?

[Obi-dad]

I have noticed a large drop off in PAR from T5s after 6 months - but I think this is due to not enough ventilation in my canopy.

I wasn't keeping track of PAR month by month, but I am guessing it was a constant drop off due to the improper ventilation, not a sudden drop off at 6 months.

[The Grim Reefer]

I had 2 of my lamps that were hurting after a year but they were in the hottest part of the canopy, I ran 1 fan for the first couple months and I am sure that killed them. The others were still pretty bright. I wish I could remember which was which so I could actually take measurements. I am thinking that on the new tank I will just take PAR readings on the lamps with a few hours on them and change them out after they drop 30% from there. With all the fans running and with vent holes in the lid I had an Aquablue that had been running about 3 months and it was within 10% of one that had been running an hour.

[Obi-dad]

I am actually going to experiment with the 'dark side' - I bought a couple of Icecap MH ballasts and am replacing 2 of my 6 T5s with them. I loved my T5s, but lately have decided I am missing the shimmer lines of my old MH tank. The risk I am running is that the tank is in the line of sight when I am working at my computer so I may be distracted too easily by the shimmer lines. I am also very worried about the heat during summer, but I'll cross that bridge next summer.

I am not betraying my belief in T5s though, my other tank will remain all T5s. :)

[amheck]

Thanks for the link. I missed that first time around. That certainly gives me hope!

Aaron

[dwdenny]

I am still going to run a 4X39w on my 40g breeder. How many fans should I be running in the canopy to help cool things down. The back is completely open and I can drill some 3/4" holes in the top if need be as well.

[The Grim Reefer]

I'd try a couple fans. I had mine blowing in from the lower back

[amheck]

What fans work well? Is there a clip on that works, or are we talking computer fans? I just got my Tek hood and it runs a little hotter than I thought so I was thinking about putting a fan on the top.

[The Grim Reefer]

Check marine depot in the DIY parts section they have some fans. Computer fans will work, so will clip ons. It really depends on your particular situation

[amheck]

Clip on would be best, cause I don't have a hood. Best thing to do is to rummage around home depot or lowes?