New lighting for 5 gallon tanks

[An t-iasg]

Currently I have two 5 gallon tanks, arranged in an L-shape, with a regular 15 watt aquarium bulb going diagonally over both tanks. I would like to change to this light for each tank:

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=11382&N=2004+113345

There are two bulbs in this fixture. I would just like to use one bulb to have 1.8 watts per gallon. Is it ok to run this little fixture with only one bulb? If so, which one do I get - the mini Aqualight for the 10000K daylight bulb (I would remove the actinic one) OR the mini-freshwater Aqualight, and remove one of the 6700K bulbs (leaving another 6700K bulb)? I do have a glass canopy. Since the bulbs are both 9 watts, is it a matter of preference for the color temperature? The 10000K will appear a bit bluer and the 6700K will be a little whiter in comparison, right?

 

[czcz]

I think you'll need all 18w over 5g for the higher light plants you've listed. I perceive 6700K and 10000K as you expect to, but know others see 10000K as white and 6700K as yellow-ish.

 

[An t-iasg]

Thanks, czcz! The plants I got about a month ago are doing ok -- but not great. The bacopa melted right away into a slime and the Echinodorus angustifolius is now in a critter keeper until I can get it back to the hatchery. It won't do well in the light I have. (It's doing fairly well under a bright lamp!) Its roots are getting quite big in the critter keeper and I think it's too big for my tank, so I'll return it. Some of my dwarf sags in the tank are turning yellow. Overall I'm happy with my first large-scale planting attempt but in order to learn more about the plants and continue with them, the lighting I have needs to be upgraded. It was fine for the few small crypts I had for awhile but to keep anything else, I need to upgrade the lights.

 

[malkore]

with smaller tanks, the wpg 'rule' breaks. basically there's a minimum amount of wattage needed to grow higher light plants, and 3wpg over a 5gal, or 15watts, just isn't sufficient.

With smaller tanks you really have to play around to see what you can do. I have a 5gal with a 10watt all-glass 10000k screw in power compact, and I've never seen my anubias bartari v. nana grow better.
Once a week I dose 1mL of Flourish and a half cap of Excel.

 

[An t-iasg]

Thanks, Malkore...is the 5 gallon you're talking about an Eclipse hex? I have one of those also (empty at the moment) but it was easy to grow plants in that tank. The tanks that I want to get better lighting for are the two 5.5 gallon All-Glass tanks on my kitchen counter. I have a pic in my gallery. The picture is old but the placement of the tanks on the counter is the same.