20w screw-in cf?

[BigDaddy]

Yeah.. those "linear" cf screwins are more effecient than the corkscrew ones... but still fall way short of a true linear.

First off, the tube length is marginal.  Then, you have the tubes doubled over each other.  Both of these conditions cause restrike.  Restrike makes the bulb less effecient and also makes the bulb hotter.  Hotter bulbs also produce less light.

So... while they might be okay for planted tanks or fish only tanks, I doubt they would support even the most hardy corals.

[squeeker]

OK, gotcha.  I get it now.  Thanks!

[Mettle]

If you had a highly polished reflector on the inside of the hood would that not help with the light from those screw-ins? I mean - tinfoil would probably work for this. Because they are 10000k daylight on one side.

Might be an interesting experiment if anyone's willing to fork out the $$$ for the bulbs. They are rather expensive though! Might be cheaper to simply invest in some type of true cf lighting for the tank...

[BigDaddy]

All a reflector is going to do is stop a VERY small amount of restrike from the bulbs that are towards the top of the hood.

Again... they just don't emit enough energy

[Mettle]

I asked on some other forums I post on and people said they had success with them on nanos that were 10 gallons or less and were able to grow some easy corals with them... That's just their personal experience.

One person said they had great success with their 5 gallon nano and these bulbs.

[squeeker]

Well, I am going to try my setup anyway... I'll let you all know how I fare!

[DARKPHREAK]

Easy corals... They will live but take a long time to grow(if at all) compared to if you had the proper type and amount of light...

[Mettle]

Easy corals... They will live but take a long time to grow(if at all) compared to if you had the proper type and amount of light...

Well, like I said it's second hand experience. But 'great success' seems to mean a little more to me than minor growth.

Let us know how it goes, Squeeker! Do you know anywhere in Ottawa that has these in stock? Or are you ordering them online? If you do an order let me know, I may be interested in a couple as well. We could split shipping!

[DonCorleone]

Big Al's East has them, as with the 6700K ones I got for my planted 10G two years ago...

[gvv]

I think what he's getting at is the fact that compact fluorescent screw in bulbs are designed as regular light bulbs; that is, throwing light in a fairly spherical direction (which is ideal as their intended purpose is to replace regular light bulbs).

Sorry, but I don't think even linear ones are unidirectional  
As there are no  such lamps, everything depends only on the lamp intensity and good reflector. As I understand BigDaddy, the corkscrew lamps have less intensity per electrical watt (as it is power consumption and not light intensity is mentioned by watts on the lamps. And intensity on these lamps is measured by lumens.  So, "watt-per-gallon" does not work... In SW it is actually "watt-per-surface-sq.foot" for specific type of lighting: MH, VHO, NO... At least as I read on SW sites, like AC, RC and some other.
Now, the question: for FW plants the intensity is much more valuable in comparison with wavelength. What about corals?

Regards