T5 vs. PC?

[saltaddict]

reefraff
It sounds as if we are both running the same for T5 quick question about your post. Are you saying that you measured the PAR at 18.5 inches for both the T5 and MH and it was double what the 150 DE HQi was giving you?

 

[reefraff]

6 80 watt T5's. 4 IC SLR reflectors, 2 SLS tek reflectors, 2 660 ballasts. 2 aquablue lamps, I ge 6500K, 2 Blues, 1 Blueplus.
PAR measured at 18.5" below surface, just above the sand with lamps 3.5 inches above the water. 145 umols
3 20K 150 watt DE halides with 4 24 watt and 2 36 watt PC actinics. PAR measured 18.5 inches below surface with lamp approx 4" above water. 65 umols.
Actually worse than I thought. I forgot to correct the output of the halides. My sensor over reads fluorescents 10 percent and halides 8 percent. I accounted for the fluorescent over read but forgot to do the halides.
The 20K halides won't have near the PAR the 10K's will. Just hope it willbe more than double which is intirely possible.

 

[saltaddict]

reefraff
Very interesting I would be very interested in knowing those results when you finaly do the test with your 10K bulbs. I am surprise by your results. I had been told in the past that the T5 80W where equivalnet to 150 W MH . But by what you are saying they could be equal or better than the 150 DE which I was told was equivalent to 250 W mogels.
I have purchased some SPS that were browned out at my LFS while under MH sitting about 10 inches from the surface of the tank and these corals have colored up beutifuly under my T5 about 8 inches from my T5. Not sure it if was all do to lighting or water quality played a roll but what you are telling me could account for the changes I have seen.

 

[reefraff]

I have heard that a cheap 150 DE will do what most good 175's will. A top of the line 150 might come close to a cheap 250 but I would never say they were equal. Kind of like cars, there is no replacement for displacement.

 

[saltaddict]

please post your results in the future or e-mail me at tony@ascent.com when you get them thanks

 

[bolobean]

saltaddict, what do you mean when you say you have to override or push the wattage on a t5 from 80 to 10o, is it simply a bigger ballast or watt. thanks

 

[saltaddict]

I use a Icecap 660 balast to run three 80W T5s . Although I can't prove anything I was told this overdrives the bulbs and they are really driven at 100W as oposed to 80W . This makes them brighter but shortens their life. Normaly T5 are rated for 18 to 24 months but if you overdrive them they should be changed after 12 months

 

[reefraff]

According to Ice Cap overdriving T5's on their ballasts will not decrease the life of the lamps as long as you have the right venting to keep things from overheating. Their current estiments based on their testing is 18 months for the blue, actinic or aquablue lamps and 36 to 48 months for the GE 6500K daylight bulb. The longer they test the more the estimate goes up. They say because of the high frequency they run the lamps at it compensates for the wear and tear of overdriving.

 

[saltaddict]

reefraft
If what you are saying is true that kind of shoots that MH are much cheaper theory that was posted on this thread. I thought that was of base but what you are saying blows it out of the water. Can you explain the downside to me? They cost the same they give more light and the bulbs last 6 months longer were is the downside?

 

[reefraff]

No shimmer lines, at least not as good.
I have been running the overdriven T5's for over 15 months and had 2 lamps fade but they were at the front of the canopy which is where the most heat is. Now that I run fans things stay nice and cool compared to no fans.
You really have to take into account tank demension when deciding if T5 is a better deal. A 5 foot long tank plays right into the 60" T5's where halides would leave you deciding between 2 or 3 lamps. Tanks over 18" front to back play into halide because they provide the good spread back to front while you are now getting into having 8 T5's. I wouldn't use T5 and anything much over 24" tall unless it was going to be well thought out so high and medium lighting critters would be in the top half.