CFL light choices

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jemanser

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My CFL over my 55 gallon are old and need replaced The hood is a JBJ and houses 2 96 w bulbs ( ~ 32 inches long each). I run one at a time( 2 watts/gallon) since I have a low tech tank ( dosing wiith liquid Carbon source). The plants look OK - growing well and with some brown algae on the leaves and substrate and few clumps of hair or staghorm algae( few mm long on just a few leaves)- not much. My question is which 2 lights would you purchase to replace the 2-6700k daylight bulbs: 2- 96 Watt Blue/White Combo/6500K Compact Fluorescent or 1- 96 Watt 7100K Blue Compact Fluorescent with 1-96 Watt 6500K Daylight Compact Fluorescent or lastly 2-96 Watt 6500K Daylight Compact Fluorescent. Is the 96 w 7100 blue ok for fresh water plants? From what I have read the fresh water plants need both light wavelengths in the red and blue range( not really the green range). The supplier states the 7100 blue is not for fresh water. Although they give me the K rating, the wavelength spectrum isn't given with the description of any bulbs. I believe the K rating between 5000k and 10000K is good for FW plants. CFL of this size are becoming rarer with LED now in vogue so my suppliers are limited. Perhaps I am splitting hairs regarding the 3 choices. Any advice would be great
 

ROYWS3

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2- 96 Watt Blue/White Combo/6500K Compact Fluorescent - I'm assuming that lamp is blue on one side and white on the other, correct? If so I would say you could use those or these 2-96 Watt 6500K Daylight Compact Fluorescent

If I'm reading your post correctly and you're just running one lamp at a time, this combo: 1- 96 Watt 7100K Blue Compact Fluorescent with 1-96 Watt 6500K Daylight Compact Fluorescent wouldn't really be beneficial as one day you'd be lighting with a daylight lamp and the next day it would be a purely blue lamp

You are right in saying blue wavelengths are beneficial to plant growth but not as a single source. I get excellent growth with a 10000k/actinic combo but both lamps are lit together the whole time my fixture is on

hope this helps
 

jemanser

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Nov 22, 2005
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Sorry for the confusion but you are correct - I would either be running 96w 6500K day light for 8 hours or 96 w 6500k day light for 4 h and then the 96 w 7100k blue light for another 4 hours or the dual 96 Watt Blue/White Combo/6500K Compact Fluorescent for 8 hours. So having clarified this I assume you like the combo or the straight 6500k. Thanks for your help
 

ROYWS3

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Agreed. I would choose one of those two and eliminate the 1- 96 Watt 7100K Blue Compact Fluorescent with 1-96 Watt 6500K Daylight Compact Fluorescent as a choice
 

jemanser

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Lighting can be complex so bare with me please... the more I read the more confusing it becomes. I understand albeit superfically the importance of light spectrum and K ratings as well as PUR/PAR values. So when a company states they have a 96 Watt 7100K Blue Compact Fluorescent - is there simply more light in the blue spectrum in that 7100 bulb. vs the daylight 6500k CFL? Ok then is there such a thing as a 7100k white compact fluorescent ?[FONT=Verdana, Arial, Helvetica] I understand for instance one 6500k light is not the same as another since there is more than one way to mix light /wave lengths to achieve a certain kelvin temperature rating[/FONT]. Having read more than I like about light - I have come across info stating that 6500k light does not penetrate more than one foot so if my 55 g is 18 inches would I be better off going with a higher K rating like 10000k/ I am not trying to be confusing but there is a lot of info out there and it can be a little contradictory. Short of purchasing a PAR meter I guess often trial and error seems to be the best teacher and also utilizing the expertise of people on this site with vastly more experience then me. Perhaps I should upgrade in the future to LED lighting- I hear there are many advantages regarding energy usage and preferential wavelengh selection.
 

FreshyFresh

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Unless the replacement CFLs are a bargain, I personally wouldn't spend the money re-lamping this fixture. A whole new 48" T5HO 6500K can be shipped to your door, lamps included for ~$45. http://www.ebay.com/itm/T5-Dual-48-...036?pt=LH_DefaultDomain_0&hash=item43c7f89d64

They are so inexpensive now given T8s and T5s are going the way of the dinosaur in the aquarium realm.

I've had one for over 2yrs and it's been great. Re-lamped it after about 13mo for ~$20.
 

jemanser

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Nov 22, 2005
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Now that's an eye opener- the 96watt CFls are 23 dollars each- thanks for this advice. I guess I would need one over a 55 gallon- low tech tank- is this too much light ?
 

jemanser

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Nov 22, 2005
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I looked at the description of the light and it looks perfect for my tank with 2 54watt bulbs,, thanks again
 

FreshyFresh

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I looked at the description of the light and it looks perfect for my tank with 2 54watt bulbs,, thanks again

Happy to offer suggestions! Yep, it's ~108watts total. It's a lot of light over a 55, but I find low light plants do real well with this style fixture provided you shield them with some floating plants like water sprite or wisteria.
 

Gregg

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If you are even considering changing out your lighting, the newer T2 lights are a good option to the LEDs for less money and good output with power wattage used
Many have used these for planted aquariums too

G
 
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