soft white bulbs... good spectrum?

[DarkSoul]

OK...why not...the fixture rating (lets say 60W) is rated for the HEAT of a 60W lamp. a 17W spiral CFL is ~ equivalent to a 60W bulb....but it's MUCH cooler. I admit I haven't done any scientific studies, but I bet it would take 3-4 17's (51-68W) of CFL to even come close to the heat of a 60W bulb. and since the heat would be more spread out, that changes the equation too.

Maybe someone will confirm/correct me on this?

For example, many folks use 2 17W spiral CFL's in the old dual 15-25W fixtures with no problems...and get WAY more light.

I have a light over my shower that is rated 40W max. I use a 23W CFL (rated 100W) in it...and it's still way cooler than a 40W bulb.

--DB

your both wrong on some points.

restrike happens due to the reflector shape, even tubes suffer from it if they are in a reflector that is flat on top. no matter what, you will suffer from restrike, even in a well designed reflector.

the wattage rating, and comparison on the packages are comparing the light output of the bulb. a 15W CF is equivalant to 60W of incandescent light, in terms of lumen output.
CFs also have a much higher lumen per watt rating than incandescent bulbs.

sockets are rated for certain wattages based on what the contacts can handle. it is related to heat, but only because pushing more wattage than the rated amount will generate heat in the socket contacts, causing them to melt.
putting a 50W CF bulb, into a socket rated for 50W is just fine, no matter how huge the bulb may be, since you aren't exceeding the sockets maximum rating.

the heat of CFs is actually pretty close to incandescents. same goes for tubes, the difference is due to the surface area available to dissipate the heat. a CF is much more compact, and has little area for heat to dissipate, so they seem hotter. a tube will generate just as much heat, but it is dissipated much faster due to the long surface of the tube.

 

[ThePBM]

i've tried both those spiral cfls and straight tubes, and maybe it's some other factors in my setup, but i feel like those spirals are a huge waste of wattage in terms of getting it down into your tank. it emits light in all kinds of directions and you need a much larger reflector that i would consider to be an eyesore. for the price of what you paid for that bulb, you could've had a fixture AND bulb of a t5 or t8 straight fluorescent tube in the 6500k+ range.

 

[kj5kb]

~ 2 WPG (2 ~30W t10's) in my 30 Breeder is plenty for the low light plants I have in there. Anacharis is growing like a weed.

Rotala wallichii doing well, too...and it's a mid light plant.

Also have: water wisteria, Java moss, Java ferns, red crypts and anubias in the tank. I'm sure the growth would be faster with CO2 and more light, but I'm happy with it so far. We'll see how it goes once I move all of it to a taller 40 Breeder...may need more light then.

 

[DarkSoul]

the sprials may in fact not be as efficent as a tube as far as light direction, but as it is right now, there is WAY more light in the tank than there was with the single 17W tube.

I paid $15 for that large bulb.... I can buy a reflector, fixture, tube, ballast for $15?? I dont think so.
I already had a T8 in it, and replacing it with another T8 would do no real good, as it is still only 17W.

I now have 60W.... the bulbs I already had, the sockets were free, I already had angle brackets and screws..... so this cost me nothing, and gained me lots.

besides im not about to go and buy another reflector/hood when Ive already spent $60 on this one.