t5 vs pc

[Don E]

Hi- sorry if this is a common question- the forum won't let me search using the terms "T5" or "PC" grrr.

Anyway- I'm looking to light a 20g tall. I used to use a coralife 2x65 pc unit, and was happy with it- but people tell me t5's are cheaper and cooler.

What I'm confused about is the equivalent wattage. What kind of t5 setup would I need to approximate the lighting I used to get with the 2x65 PC unit?

Thanks, all

don
(back in Victoria again)

[kwirky]

if your tank is tall, I'd go with the PC's or MH lighting.

Remember, T5's are normally driven and designed to light plants. Their efficiency is owed to their small size allowing them to be reflected optimaly. They still lose about 50% of their light after 12" of water depth.

PC's loose their light at about 16" or so.

Mh's on the other hand are point light. 150/175 MH loses 50% of it's light at about 20" away from the point. 250 at about 24" or so, and 400w at about 30"

so comparing watt for watt is hard when you have tank depth involved.

[Don E]

Thanks for the reply- that's interesting. Hmm. Mind you, a 20 Tall is still not all that tall- 16 inches, I think?

I may just go back to the 2x 65.

Is anybody out there using t5's with a 20T? If so, how many, what length, and are you happy with them?

thanks

d

[StirCrazy]

I would stay with your PC's The difference between PC's and HOT5's is hardly worth looking at.. and normal T5's are not as powerfull.

Steve

[Dale]

Hi Don.

I don't have a firm opinion either way but my 75G. tank is lit by T-5's and doing well. I guess it depends on what you plan to stock.
One thing I did do was to build a rockwall using a light diffuser background for support. This allowed me to raise the rocks up and to put my highest light demanding corals on top. Both my hammer and candycanes are doing well anyways (I don't have "high" light corals). The top of the rock ridge is about 6" from the bulbs.
I have two units with 2 bulbs each:
10,000K
6700K
Actinic
Colourmax (came with the unit-when it's time I'll replace with 10,000 or 6,700)

Here's the T-5's in the canopy



and the tank from a little while ago


________
growing marijuana

[albert_dao]

HO T5's are vastly superior to PC bulbs and can, if done properly, exceed MH's in PAR output.

Look at Iwan's tank on RC and any doubts you have should dissapate.

Here's some further reading:

http://reefcentral.com/forums/showth...hreadid=878433

[Reefer Rob]

PCs do not compare at all to T5s with the right reflector. I run 324 watts of T5 over my 72 Gal bow, and all my sps is doing great. Big difference from the 260 watts of PCs I had before (didn't have SPS then). 2 or 3 times the light and way less heat.

Rob

[StirCrazy]

Ok you guys are getting confused.. take reflectors out of the question as that is not what were talking about... a proper reflector on a 150 watt DE MHwill make it seam like it puts out more light than a 400 wat SE MH.

compare aples to aples.. a PC is actualy a T4 which is nothing more than the tube size.. oh and by the way the smaller the tube size the more intence the light is for the same given wattage.

now a 96 watt PC is a 6 foot T4 folded in half so it is 3 foot long. Because of the fold there is a little light loss in the area where the tubes block each other but downwards there should be the same light out put.

I know where there are some T5's running.. maybeI will have to take my tester down there and get some hard numbers on this. the question is how do we compare them? do we do wattages or by lenght?

watages is a little un fair as it doesn't give and acurate measurment of coverage, so I am thinking by lenght.


Steve

[Reefer Rob]

The best testers are corals themselves All the theory and testing aside, the bottom line is they work well. Some of the nicest captive reefs in the world are being kept under T5 lighting. If you know of an SPS tank being kept under PC lighting I would like to see it, so far I have not been able to find one. Before I switched to T5s I did a lot of looking around, and could find very few people who acually used them who didn't like them.

Rob

[TheReefGeek]

take reflectors out of the question

Why would you not consider the reflectors? One of the big advantages of T5 is that they are small and can be reflected really well with individual reflectors. In practice we all use reflectors, so they are very important when considering light setup.

I would choose HO T5's with icecap reflectors over PC with any reflector.

As mentioned SPS can be kept under HO T5s, but not under PC, so no matter what theoretical testing is done, in practice (which is what counts for me) HO T5s outperform PC.

You have to make sure you are getting actual HO (High Output) T5s, not just normal ones.

The T5s are going to be more expensive to buy good reflectors, but it will be worth it if you want to keep higher light requiring animals.