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I currently have a 65w CF over my 29g, and while that seems to be doing ok, it's just not enough for some of the higher light plants that I would like to try. I believe my next option would be to go to a dual strip CF light which would take me up to 130w, which is way more light than I need.

I've recently been looking at T-5 lights and I was amazed to find out how much cheaper than CF's they are. For example, a dual-strip 30" 18w T-5 at Big Al's is only $36.99US. A dual strip 30" CF is $159.99US.

Maybe someone needs to set me straight on this. What's the difference in light intensity between the two? I thought I saw an article comparing T-5 to CF on this forum, but I can't locate it.

renoharps,

I think you are doing your best you can to confuse yourself

A dual strip 30" CF is $159.99US – Well that would be 130w, as you mentioned earlier in your post.
A dual-strip 30" 18w T-5 at Big Al's is only $36.99US – well, that’s 36w, almost 100w less.

And if that is not enough:

Regular fluorescent lights need replacement more often (supposedly between 6 and 9 months vs. 12 to 18 months) and need way more space for the same wattage.

I personally would say that 130w is really a lot over 29G. What are the plants that are not doing so good?

Hope this helps,

Ingo

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Proud Member of the New Jersey Aquatic Gardeners Club

I am setting up a 29g and I ordered the 30" 65w fixture. I also want more light and thought about getting that T5 fixture also...if both would fit. I have ordered the 65w fixture and it should be here Thursday so I don't know how much room will be left if I decide to get another fixture.

I also thought about the 130w fixture and with help, decided it was too much light...especially without CO2.

Do you think both the 65w fixture and the dual-strip T5 fixture will fit on top of your tank?

If I understand you right...that is what you want to do? It would give you about 3.4 wpg...which is what I actually want. You could grow some higher light plants and probably some plants with more color.

I think T5 has to do with how big the bulbs are (not length but width). I don't think they are as powerful as CF bulbs.

edit: Here) is a post about the differences in lighting. Hope it helps!

Last edited by GirlieGirl8519 at 16-Jan-2006 12:32

Last edited by GirlieGirl8519 at 16-Jan-2006 12:34

*Kristin*

Ingo,

T-5 bulbs are 3-4 times the intensity of a similar wattage T-12 bulb. I think CF bulbs are basically just a T-12 folded into a smaller space making them more intense per inch. I'm just trying to make sense of the T-5 to CF comparison.

I looked at some 18w T-5's at my LFS and they seemed just as bright as my 65w CF fixture.

So what I am saying is that an 18w T-5 does not equal 18w of CF. The article that Girlie referred to doesn't directly compare T-5 and CF wattage unless what it is saying is that 65w of CF is the same light intensity as a 65w T-12 just folded into a smaller space.

So, given that a T-5 is 3-4 times the intensity of T-12, does that mean an 18w T-5 equals 54-72w of T-12 light?

Also, from what I have read Ingo, a T-5 bulb has a 20,000 hour lifetime. that's way longer than even a CF bulb.

Last edited by renoharps at 16-Jan-2006 15:14

renoharps,

I got it now .

What you say makes somewhat sense. But here are my thoughts (without reading anything about it):

A single T5 is better than a T12 as it has more light that bounces off the reflector and finds its way into the tank past the bulb itself. It still has only the same wattage (I don’t know about Lumes though, so all my thoughts might be wrong anyway), but the fact that it is much thinner allows the light to pass (bounce off reflector).

I haven’t measured my CFs but there is no way that they are the same diameter than T12s, maybe T8 or my guess T5.

So packing T5s tightly will have the same effect as using CFs, or at least close to it. But you would need a few T5s to achieve the same result and they would block the light as well.

Just some thoughts,

Ingo

Edit: While word on CF is that you can use them pretty much until they burn out, Ts are supposed to be replaced way before the Lifetime value is achieved as they seem to change color spectrum and intensity with age. But I am no expert with this.

Last edited by LITTLE_FISH at 16-Jan-2006 15:23

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Proud Member of the New Jersey Aquatic Gardeners Club

Thanks for replying Ingo.

After looking at the prices of the fixtures and the replacement bulbs, I'd like to know the difference between CF and T-5, watt for watt. My LFS guy is sold on them. The one I looked at that has two 18w bulbs seemed just as bright as my 65w CF.

I haven't found a lot of info yet on the web about T-5's and comparing them to other fixtures. I was hoping that someone here had some experience with them.

I sent an email to ESU. Hopefully they'll respond.