Old bulb went out, what kind of new bulb should I get?

[icecubez189]

Hey guys, I have a 20 gallon tall that's lightly planted and also a piece of driftwood. I would tell you the species of plant I have but I forgot it long ago! might be amazon swords. also a few mixed species of tetras.

I pretty much used the 15 watt 18" fluorescent bulb that came stock with my All-Glass Aquarium hood, inadequate, i know. I've had this tank setup for about three years now and the swords look all right. Now that the bulb went out, I figured this would be a great time to provide the plants with a little something more and bring out a more natural color to my fish and the tank itself. but there is so many different bulbs with different kelvin ratings, I'm confused and would like to learn more about kelvin ratings and how it affects color and the plants.

I want to give my tank a more natural color. There is a good aquarium store near my house which has a huge planted tank. The water has a yellow, sunlight look to it and I would love to know which type of fluorescent bulb puts out this warm color.

thanks in advance!

[Ozymandias]

it problably in the 6,500K to 10,000K (thats Kelvin) range, its what most people consider good for plants and still pleasing for the eye to look at at the same time. so something in that range is probably what you want to get.

[Jspigs]

It is my understanding that the best k range for plants is between 5,500k and 10,000k but preferably close to (or exactly) 6700k. 6700k bulbs put out a whitish color light similar to daylight.

[fishorama]

If the swords were growing ok 4 or 5 months before you can probably just replace the bulb. Fluorscents drop off the amount of light before they are burned out. It's usually suggested you change the bulb at least once a year. Swords aren't really light hogs.
Like the others said 5,000-10,000k is good. You can't add more light without a different or additional fixture.

[icecubez189]

thanks guys, that's exactly what i needed to hear.

which of these Coralife bulbs would put out a more yellowish color? i'm not sure if that's what "sunlight" looks like. It might not be the 50/50 since that has an actinic blue, am I right?

http://www.petco.com/product/5707/Coralife-10-000K-High-Intensity-Purified-Super-Daylight-Lamps.aspx

http://www.petco.com/product/5710/Coralife-50-or-50-50-percent-Natural-Daylight-6-000-K-Fluorescent-Bulbs.aspx

Also, if there better websites with a larger selections of fluorescent bulbs, please do tell, thanks!

[Ozymandias]

defiantly not the 50/50 (actinic has no effect on plants that i know of) the 10,000K will be fine for the plants but it will be more white color then anything. the pet store with the planted tank was probably using 6500K because that dents to have a more yellowish color to it then a 10,000K bulb. so look for the 6500K if you can it will most likely say it's for plants.

Edit: just did a quick search on Big als for stuff that might be good for your tank. there both zoo med but there are other bulbs on there for you to look at.

8,500K (http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18358/si1381114/cl0/zoomedflorasunmaxplantgrowthfluorescentlamp18t8)

6,500K (http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18358/si1381132/cl0/zoomedultrasun6500ksuperdaylightlamp18t8)

[kj5kb]

Hmm..."Yellow" and sunlight don't really go together in my mind...except maybe sunrise and set.

Perhaps the tank at the store looked yellow in relation to the ambient lighting.

I suggest picking up a "daylight" 18" tube at your local Home depot/DIY/lighting place...that will be ~ 6500-6700K. Cheaper than an "aquarium" tube & cheap enough to try out.

I advise against getting a "plant" lite or gro-lite from the DIY store; they tend to be very pink...fine for blooming houseplants but not so good for aquarium plants.

[Jspigs]

Hmm..."Yellow" and sunlight don't really go together in my mind...except maybe sunrise and set.

I was thinking the same thing.

Maybe there were tannins or something in the water that caused the light to look different.

I know when I have tannins in my tank with 6700k bulbs it can look yellowish but when I put carbon in the filter (carbon removes tannins) the light looked whitish like daylight.

Even in my bro's new tank the light is around 5100k (not sure the exact rating but that is what I think it is) and it looks yellowish when there are lots of tannins but when the tannins are removed it just looks like whitish daylight.

[WeedCali]

make sure you follow the max wattage the light fixture allows ;)

[icecubez189]

thanks for the links, i'll be sure to check them out. aquarium lighting does seem overly expensive, i suppose Home Depot has the same type of lighting, i just have to know what to look for, thanks for that suggestion. my strip light hood is 24 inches long and says 120 volts, 19 watts, 60hz. The stock light was 15 watts. Do they have T8 18" bulbs in 19 watt varieties? Or are they generally all 15 watts (from what I see).

it was probably tannins then, i don't remember seeing driftwood but the tank was heavily planted.

edit: also, zoo med and coralife seems to be the two popular brands in aquarium lighting. are both pretty much comparable in quality and longevity or is one brand generally better for the money than the other? thanks

[kj5kb]

The stock light was 15 watts. Do they have T8 18" bulbs in 19 watt varieties? Or are they generally all 15 watts (from what I see).


18" tubes are generally 15 watts; I've seen a few 17's...but the difference in light output is negligible.

I have tried to grow low-light plants in a 20G high with a single 18" tube.
I got hornwort and java moss to survive but they did not grow well and weren't as green as they should be. In another 20G High I had 2 23W daylight CFLs with a decent reflector...it was full of nice Red Crypts and spiral val.

FWIW, The 18" tube is the same light that comes with many 10G hoods. It's just enough light for low light plants in a 10G. In a 20G High, it's fine for looking at your fish, but pretty inadequate for plants (another reason not to spend a lot of $ on lamps). Glad your swords are doing OK.

[icecubez189]

thanks for the input. 0.75 watts per gallon isn't very much at all in a planted tank but i wanted to try it out. they aren't as green or lush as i know it can be (especially when algae covers the leaves) but i'm glad they are still alive after all this time. I dose with Seachem Flourish every once in a while.