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Discussion Starter · #1 · (Edited)
I have a 46gal bowfront (36W x 16D x 20H) that is low light/low tech. The tank will not be heavily planted. The hood holds one 24" fluorescent bulb with a ballast max of 20 watts, but there is room for a second bulb with installation of a second ballast. Is the one bulb enough? If not, can anyone recommend a new lighting set?
 

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I have a 46gal bowfront (36W x 16D x 20H) that is low light/low tech. The tank will not be heavily planted. The hood holds one 24" fluorescent bulb with a ballast max of 20 watts, but there is room for a second bulb with installation of a second ballast. Is the one bulb enough? If not, can anyone recommend a new lighting set?
One single 20W flourescent bulb over a 46G is way too low of a light. Two of these bulbs would put you at the low end of low light. You'd be able to grow a few things, probably enough to make it look nice, but it would definitely be very low light with two bulbs ... with just one, pretty much impossible to grow anything.

Btw, as a side note based on how you phrased your question ... whether the tank is heavily planted or not makes no difference to the amount of light you need, you can cover the whole tank with (for example) java ferns (which are low light plants) and still need the same light (focused beam lights excluded) as if you only put in one tiny java fern plant.

Harry
 

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Discussion Starter · #4 ·
How does ambient light, if any, figure into the equation?
 

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How does ambient light, if any, figure into the equation?
Like already mentioned, ambient light is never part of the equation ... it's actually usually a bad thing because it's so uncontrollable and instability is a bad thing in planted tanks since algea is what happens when instability happens.

Harry
 

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I think 2 T5NO bulbs give about the same intensity as one T5HO bulb. And, one T5HO bulb should give very good low light intensity for that tank.
 

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I think front-to-back coverage might be an issue with just one bulb, Hoppy, since the bowfront tanks are 16" deep at the point of the bow.
Yes, I agree. Unless the single bulb fixture is hung a foot or so above the tank the front to back uniformity wouldn't be very good. But two T5NO bulbs would help in getting more uniformity, and about the same intensity.
 

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Discussion Starter · #12 · (Edited)
I'm thinking of going with 2x18 bulbs (b/c 36" is too long), but I'm concerned that may be not bright enough even for a low light. I also understand that 2 T5HO bulbs is too bright. I don't want to raise the height of the light. Any recommendations? Anyone know of a good mix in the 24" , 5500K to 10,000K range?
 

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Discussion Starter · #13 ·
Thinking of buying 3 GE Slimline fixtures (no reflectors) from Home Depot since they have connections for serial lighting. Would replace the soft white F13T5s with 2 F14T5NO 6700Ks and one 10,000K.

1) Anyone know if the Slimline can hold an F24T5HO?
2) Would 2x24T5HO be too bright for my low-light 46gal?
3) Anyone know what kind of ballast the Slimline has?
 

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Any bulb shorter than the tank is long will leave the ends of the tank less well lighted than the middle. Any length T5HO bulb will give about the same light intensity in the middle of the tank as any other length. All the wattage means is how long the bulb is. Based on that, 2 T5HO bulbs, whether 24 inch or 36 inch long will give more than low light on that tank. Why not look at PC bulbs, which can be about 34 inches long, and could give low light intensity?
 

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Discussion Starter · #15 ·
Thanks, Hoppy. Being that the tank is acrylic, it is rimless and has a special cutout for the lighting. The remainder of the length of the tank is covered/surrounded by acrylic. It will be a lot more difficult to install a new hood. I, therefore, would like to use the existing 24" hood. Any other suggestions? Would really like to get it going. Thanks.
 

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