Medium or low

[ahud]

Can you go medium light and still skip Co2?

[Diana]

You are right on the edge with 'medium light'.
When I had only 1 wpg I started using Excel, potassium and iron and this helped a bit. Light was really too low for the plants to really thrive. The one tank that was closest to a window showed this: The plants in this one tank grew like crazy when I added the supplements they needed.
When I doubled the light (2 wpg, and moved more tanks closer to the windows) the Excel really helped, and I had to add more fertilizers. I started with EI, and then backed down until I did not have to do large water changes.

The 2 wpg were varied:
Tanks ranged from 3 gallons to 125 gallons.
Lights were almost all fluorescent, T-12 and T-8. Assorted bulbs: Plant/Aquarium, 'Cool White', 'Daylight' and others. Each tank pretty much had mixed bulbs, so they were getting more varied wave lengths than if all the bulbs were the same.
Reflectors were nothing special.

[ahud]

So what would be a good lighting fixture for a 5foot 125gallon tank? I will not be adding Co2 at all.

I am just so confused on lighting.

[RipariumGuy]

For a 'five footer' I would get one or two T5NO light fixtures. They give out a good amount of light allowing you to grow all low-light plants and maybe some medium light ones.

Here is a artical (Not made by me!) that may help you- http://www.aquajake.com/blog/hardware/lighting/

[lauraleellbp]

I agree that 2x T5NO (or 4x if you buy shorter ones and put them side-to-side) fixtures would work well. Multiple fixtures would give you lots of ability to play with the photoperiod to find what works just right for you. www.BigAlsOnline.com usually has the best deal on the Coralife T5NOs and do price matching if you happen to find them anywhere else cheaper.

Or if you're handy with DIY, you could make your own. If you go with T5NO bulbs you'll probably want about 3 rows. If you go with T8 bulbs you'll want 4 rows. You'll ideally want to space the rows bulbs out a few inches apart to get better light spread across the bottom of the tank.

[ahud]

So you are suggesting two separate t5no fixtures each holding two bulbs which gives me 4 bulbs total?

What Length should I go with? a 36" and a 24"

[Diana]

That large a tank needs less watts per gallon to be low light, and T-5 offers so much light that they do not fit in the watts per gallon guideline anyway.

The better you can spread the lights both lengthwise and back to front the more equal the lighting through the whole tank. 5' is an awkward length.

More fixtures allows you to change the timing on some lights, so you might do this and still get away without using CO2:
6 AM some lights come on, but not all.
Noon-2 PM All the lights are on.
2-8PM some lights on.

[ahud]

My scape is going to include primarily Amazon swords, can somebody just suggest a light? I understand what you guys are saying, but I still don't know how to apply your advice.

I went through all the lighting research with my saltwater tank, but this is more hit or miss than that!

[lauraleellbp]

If all you want are a few swords then I'd get just two of the Coralife T5NO fixtures, whatever lengths work best to make a row completely across the top of your tank.

If you want to grow a carpeting plant and/or any stems, then I'd double that up.

[ahud]

How many bulbs per fixture?

[lauraleellbp]

The Coralife fixtures have 2 bulbs.

[ahud]

I can't find normal output fixtures?

[Digital]

If your 5 footer is like mine, just get 2 24" fixtures and you'll be good to go. Now within those fixtures if you wanted to get a double bulb setup for each, you'll give yourself room to "grow" in the future.

[ahud]

lol, but does it matter what fixtures? I think I may be overcomplicating things

[Digital]

laurelee gave you some great feedback, you should go with that recommendation.