Bulb question

[TheZoo]

I figured this would be the best place to ask about bulbs - I have a cheapo hood on my 10 gallon, with 2 15watt incandescant tube lights. Id like to switch to flourecent (or something else?), I dont like the yellow cast the incand. give off, and I dont think the anacharis does either. Is it even possible to do this without getting a flourecent full hood (which I would lvoe to do but cant spend the extra money right now)?

[Lorazoo]

i just bought flourescent for my 10 gallon. they are screw in to fit that kind of hood. they come in 10 or 20 watt. look up at petsmart.com under coralife. i got them in my LFS, 10 bucks each.

[Cathy G]

I use the DAYLIGHT bulbs at Walmart - about $4.50 a piece, 2 15 watt screw in compact flourescents. Look for the DAYLIGHT, they are full spectrum - 6500k. They work GREAT!
Cathy

[djlen]

The K-rating on the bulbs/tubes has no affect on the plant growth.
It indicates color temp. which tells the user how the tube will look to the human eye.
Anything from 6500K - 10,000K will give a nice 'white' or daylight appearance to your eye.

Len

[Cathy G]

I understood the K rating to be an indicator of the colors of light in various bulbs. Ie, soft white has a K of 3700, meaning it contains mostly blue and green light which plants don't need much of. Full spectrum indicates that the light produced contains oranges, reds and some purples... these are the 'rays' or wavelengths most beneficially to plant growth. Sometimes bulbs labeled 'plant' bulbs are higher in these wavelengths, but to our eyes they look weird. So, full spectrum contains nice looking light to our eyes, and a good assortment of wavelengths to make the plants happy.

When I specified the K rating, I was simply stating that any bulb can say it is a 'daylight' bulb, but only the bulbs labeled 5000K at least, or in this case 6500 K are true full spectrum bulbs.

Bulbs with say 18,000K really are just pricey unnecessary bulbs. The plants don't 'get' anything more out of them than normal full spectrum bulbs.

Just to clarify things,
Cathy

[TheZoo]

reviving this old thread....I got some of the mini spiral flourecents, they are 10 watt but supposedly comparable to a 40 watt incandecent. Nowhere on the package did I see anything about K ratings... There does seem to be more light now, At least, there are fewer shadows in the tanks. I couldnt find the daylight type (target, couldnt get to wal mart) but Im liking this look better than the incand. that was in there. These will work as far as hornwort/anacharis, right?

[Ms.Bubbles]

Zoo, can you tell me which brand of mini spirals you bought?
Also, can you tell me what colour of light the tank is--is the tank yellowish, greenish, pinkish?

I'm looking at getting Colormax mini Compact 10 watt bulbs, and I'm wondering how they look in the tank, and how they do in terms of growing plants.

Thanks :)

[TheZoo]

I bought the General Electric brand, "soft white 40/ regular, everyday light"... the tanks look clearer than they did with the incandecent, definatly not as yellow. If I had to pick a color, Id say maybe a teensy bit green? or is it a teeny teeny bit yellow?

[phanmc]

If you like the look, then it will work. What's important is that the light provide enough wattage for the plants, not the kelvin rating.

[TheZoo]

you know, could it be TOO bright? The spirals have made my 10 gallon much brighter, seemingly, than my 20, which has a flourecent, full hood. Dont remember the specs on that bulb though. And it is comparing white/natural gravel (10 gallon) with black (20 gallon). If I can, I think im going to try to get some other tall plants or soemthing in the 10 to block some of the light a bit.

[TheZoo]

If you like the look, then it will work. What's important is that the light provide enough wattage for the plants, not the kelvin rating.

embarrased to ask, but how much is enough wattage?

[phanmc]

For a 10g tank growing anacharis and hornwort, anywhere between 15w-30w is optimal.

For a 20g tank growing amazon swords, 35w-50w.

Gravel will play a part in how bright the tank looks, which is why alot of people use dark colored gravel so the light doesn't get reflected, saturating the whole tank. Added to the fact that the 10 tank usually is slightly less deep as a 20g and the light has less distance to travel before it is reflected compared to the 20g.