yet another lighting question...

[daveydoodle]

I'm moving a Jack Dempsey, Firemouth, and Green Terror (all about 2") from a 30 gallon to a 70 gallon tank. I've increased the number of hide spots, and rearranged the decorations. In the new tank, it comes with the standard (2) 18" bulbs. I want to put in the best possible light for viewing and wondered if their was an obvoius choice. I have painted the back of the aquarium speckled black, and have black gravel, so the brighter the light the better. No live plants.
I can only find 18" bulbs in 15 watts. So would maybe an Actinic, Power-Glo, Life-Glo, be the best choice? Higher the K rating, is that brighter? (relative to color of light - ex: blue, white, yellow?)
Thanks...

 

[CTD]

No the higher K rating does not make a brighter bulb for instance a Hagen Aqua-Glo bulb is around 18,000K (I believe) It absolutly will show some of the most beautiful colors but it is alot dimmer than a 6700k bulb in the same wattage.

 

[daveydoodle]

So then is the Aqua-Glo your choice for the best bulb for these three fish in a black on black tank? Do you know what the difference is between Aqua-Glo, Life-Glo and Power-Glo? All three according to the same manufacter are "ideal" for freshwater aquariums. My LFS recommends the Power-Glo or Life-Glo, but can't say why.
Thanks..

 

[jsoong]

K rating is the color of the bulb <higher K = more blue/UV end> ... not the brightness <that would be the lumens rating.>

For a black on black tank, I think a high K rating will look best ... perhaps 1 actinic & 1 10000+K light <if you have 2> .... but it all depends on your taste & how you want the tank to look. Some might find the almost neon like color of the fish under high K/actinics to be too artificial looking & opt for something a bit warmer. <And ignore the "ideal for aquarium" label ... that's all marketing ..... you fish don't really care.

 

[daveydoodle]

I had to try something other than the standard bulbs that came with the hood. I bought two Life-Glo bulbs (more of a full spectrum bulb) at LFS, (960 Lumens & 6,700 K) and it produces a clean, white light, however it does not extend to the full depth of the tank. I made certain that I could return them to LFS if they ended up not being what I wanted. I may try two Power-Glo bulbs (18,000 K). Maybe Actinic bulbs! Thanks.

 

[CTD]

So then is the Aqua-Glo your choice for the best bulb for these three fish in a black on black tank? Do you know what the difference is between Aqua-Glo, Life-Glo and Power-Glo? All three according to the same manufacter are "ideal" for freshwater aquariums. My LFS recommends the Power-Glo or Life-Glo, but can't say why.
Thanks..

No I'm not recommending ANY bulb, Just using the AQUA-GLO Bulb as an example of the fact that higher K does not mean a brighter bulb.

I have not tried the Power-Glo or Life-Glo bulbs, and so I can not give any advice about them.

Bulb Rating - (Listing from Dimmest first to Brightest last)

Aqua-Glo 40w (Max Lumen's = 4600) (Rated Lumen's = 960)
Power-Glo 40w (Max Lumen's = 8900) (Rated Lumen's = 2200)
Flora-Glo 40w (Max Lumen's = 12100) (Rated Lumen's = 2180)
Sun-Glo 40w (Max Lumen's = 13100) (Rated Lumen's = 3100)

Source: http://www.aquabotanic.com/lightcompare.htm