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Maybe a silly question but with a 115 uk gall tank I would require 230 watts of lighting to acheive medium growth of plants I belive from reading other posts that say 2 watts of lighting per gall for this type of growth.
Firstly would this amount of light for 9 to 12 hours a day be to much for fish particuly hatchets & other surface swimers.
Secondly 230 watts is 6/7 35 watt flourecent tubes how do you fit these under a tanks cannopy or do you use a difrent form of lightig such as halogen or arc & if so do these not cause a heat problem at the water surface, and under the tank cover a potentiall fire risk to wooden or plastic covers as I belive these lamp types do generate a lot of heat I now this all will sound prety silly to you but your opinions/advice would be greatly appreciated.As at present I seem to spend a small fortune replaceing plants continuosly.

Hi,
First, I have no idea what a UK Gallon is compared to a
US Gallon, so lets take things at face value...
You are correct, so called "Medium light demand" plants
should have 2 watts per gallon (WPG). That is alot of
flourscent tubes at 35 watts/tube.

Personally, I would choose one of two options. I would
go with the T-5 (5/8 inch diameter flourscent tube) and
either purchase or build a canopy to hold them. Or I would
purchase a canopy that uses the Compact Flourscent bulbs.
Doing either will easily get you to the 2wpg and more, if
you want. metal Halide (MH) bulbs give off tremendous
amounts of heat, and are expensive to run. The arc lights
give off even more heat, and in the wrong part of the
spectrum for plants. Arc lights can also cause interference
to radios and TVs.

If you choose the T-5 or Compact Flourscents, purchase
bulbs with a Kelvin rating around 6700 to 8800K. I would
not go higher as the light tends to become bluish, nor
would I go lower as the light tends to become yellowish
to pinkish in color.

Lights should be on a timer (so things are regular) set
for 10 hours/day. Leaving lights on longer only encourages
algae and does nothing for the plants. If your canopy is
set up so that the bulbs are divided in half (one half
per on/off switch) then I would use a second timer.
Mine is that way, and I have the primary side (runs the
light and the cooling fan) set to come on for 10 hr/day.
I have the second timer set to come on at 1000, and run
until 1400 when it turns off. This gives me 4 hours of
intense light (simulating tropical noonday sun) for the
plants that want more intense light. Depending upon your
plants, you could stretch it to 6 hours of both sets
running. When it is time to change out the bulbs (once a
year) I toss the ones that are on for the 10 hour stretch,
and replace them with the 4 hour bulbs, and use the brand
new bulbs in the 4 hour section.

If you use a combination of plants that are short or tall,
narrow or broad leafed, then the fish will spend time out
in the open under the bright light, and other time shaded
by the larger broad leafed plants.

Hope this helps...
Frank


Last edited by FRANK at 25-Jan-2005 17:25

Last edited by FRANK at 25-Jan-2005 17:26

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Frank here is the Conversion

115 gallon [UK] = 138.1092408 gallon [US, liquid]


You have covered all the advice very well as you do with all your replies

Keith

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Thanks for the above I will be looking into the T 5 lamps and timer set up but one quick question I have just had a look at a retail site after reading your replies &amp; as well as a T5 lamp they seem to be promoting a T8 lamp is this something wort considering.

Hi,
I would not even consider that T8 bulbs. T8s are one inch
in diameter and a max of about 30watts/bulb. You would
need a huge canopy to house enough bulbs for
2+ watts/gallon.

Online, look at drsfostersmith.com or Big Als etc.
In the DrsFosterSmith catalog they show kits to
retrofit a standard aquarium strip light, and they show
hoods that house up to 8 T5 tubes. If you opt for the
T5s, I would choose the SUN T5HO lights for the tank.

On the same site, they also have the Compact Flourscent
hoods go up to 576watts (6 tubes@96watts) in a 72 inch
hood. In this case I would stick with a bulb around 6700k
to 8800K max.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--