FishProfiles.com Message Forums

hi - been reading posts about 'daylight' tubes sold at hardware shops...would people be able to tell me the pros and cons of these? ie, how many watts are they, can they cause algae blooms, do they give the right light for plants, etc... i'm looking at upping my light without killing my credit card. thanks!

Daylight bulbs just indicate the "color" of the light... 6500-6700K is appropriate for plant growth, and that is termed "daylight". You can get them in any size/wattage of fluourescent lighting that I can think of offhand.

If you have a ten gallon tank, you'll be looking for a 18" bulb (I believe), and you can find it in multiple K values, but the one you're looking for is aroun 6700K or "daylight". You can find the same for other bulbs lengths, etc. It shouldn't cost TOO much if you get it at a hardware store. At pet stores, they're going to run you about $15... or they do here.

[announcer voice]Prices may vary![/announcer voice]

Last edited by Kitten at 23-Apr-2005 18:07

~Meow. Thus spoke the cat.~

The length of the tube determines the watts. A standard 48" flourescent bulb is 40w. An 18" is I think 15w but I can never remember. There are also compact flourescent bulbs. These have the bulb either bent or twisted up so that there is a long bulb in a smaller space. Some of the smaller ones screw in and others have pins at the end sort of like regular flourescents. You can get these in a much higher watt and 10g hoods often will hold screw in compacts.
The daylight refers to the kelvin rating of the bulb or the color of light it gives off. Plants need some red and blue light and people see green and yellow best. Daylight bulbs give off the best color mix for people to see as well as what plants need. These are rated around 6500-6700 kelvin. The higher you go the more blue. A completely blue bulb is 18,000k.
The kind of bulb that you don't want is incandescent. These screw in and are the same kind used in ceiling fans or desk lamps. They produce more heat than light and grow more algae than plants in most cases.

Last edited by sham at 23-Apr-2005 19:22

hi - been reading posts about 'daylight' tubes sold at hardware shops...would people be able to tell me the pros and cons of these?

Cheap, easily available,good spectrum for plant growth, Ideal for good color rendering of fish and plants (looks more natural). Can't think of any cons.

how many watts are they

Depands what size they are, as Sham said.

can they cause algae blooms

No. An imbalanced tank causes algae blooms, not bulbs. Nutrient and light levels that are not in sync with one another are the cause of most all algae problems.

do they give the right light for plants

Yes. See above.

Last edited by bensaf at 24-Apr-2005 00:27

---

Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

Those compact flourescents Sham was mentioning work wonders in a planted tank. I got a 10g setup for Xmas with the normal incandescent lights. I bought the compact flourescents (screw in kind) at Walmart (for less than 1/2 the price of pet stores) and ended up replacing the ones in my terrarium with those too. I forget what the wattage is on the small bulbs, but it looks like it brought my 10g up to 2-2.5 wpg.

The only "con" I can see with buying bulbs not meant for tanks is that some by "generic" brands, tend to burn out quick. I had one die out in about 3 months, and nearly took my bronze wendtii with it. Just be sure to try and get a good manufacturer (GE, etc.)

Last edited by harleysiber at 24-Apr-2005 18:30