Kelvin's

[Snowman]

I have 2 lights one has a 14000k bulb the other one has 2x7400k u-tubes. Which is most likely to promote plant growth ? Which is more likely to promote BBA growth ?

[Brianemone]

the 7400k

plants tend to like light in the lower kelvin range

[Snowman]

So if i was to use the 14000k light it would slow the BBA growth but slow the plant growth to, and if the plant growth slows it allows nutrients for the BBA, talk about murphy's law LOL.

Cheers Brian : -)>

[cracker]

BBA?

[Snowman]

BBA Black Beard Algae

[dan_from_nz]

flourish excell gets rid of bba (if you want to get rid of it)

[Snowman]

Thanks Dan, i've been using it for 2 weeks & it's slowly killing it. Got BBA in 3 tanks so was hoping for something cheaper as it's gonna cost $40 a month to keep treating them, working on possible excess nutrients as a cause so hopefully have it sorted soon. Cheers

[suphew]

Try running phos-sorb or a similar product, will only cost you $25 odd and will remove the cause of your BBA instead of just the syptoms.

[Dark]

you should probably know that 14000k is a trademark not a rating - i believe they are actually 6500k bulbs

in reality 14000k would be some form of black light.

[HummingBird]

I have two bulbs that are supposedly 14000k and one, by the same brand (don't know the name off hand), that's supposedly a 10000k too. Are you saying they aren't what they say they are? The 14000k ones are white and the 10000k is pinkish.

[Snowman]

My Aqua One came with two 10000k and one 15000k, 10000k is a white light and the 15000k is a purplish light. Not sure of the bulb brands though. Got two different Aqua One 3' fluro's one has 2x 7400k and the other is 14000k. How could you measure the light output of the different bulbs?

[Dark]

i believe they are the aqua-glo life-glo or power-glo range - it should be stamped on the tube at one end.

regardless, the K rating on the box is misleading, i believe it was branding to confuse consumers into continued custom - nowhere else would stock a 14,000K bulb.

this is of course assuming that they are using a standard array of phosphors in the tube (the substance that makes it glow) and have not concocted something themselves, which i seriously doubt.

their new boxes do not have the existing ratings on them, but it will probably a year or more before we see those in the pet stores

what you need to do is purchase your tubes from a lighting wholesaler - a professional. that way you can ask for 6500K tubes (which is what you want to grow plants and minimise algae).

this has the benefit of being cheaper - 6500K tubes cost me about $10 - the equivalent from a pet store is about $40.

pet store tubes also boast a service lifetime of 10,000 hours or more. this is true, they will glow for that length of time, but for growing plants you need to replace them every 2500 hours; just before they start to loose their colour which results in less plant growth and more algae. this is approx every 6 months - you can get away with longer of course but the effectiveness of the tubes will lower.

learning about the lighting requirements of your tanks is important - most pet stores will sell you whatever they have to do a job whereas a bit of research, (in my case) a much shorter trip down the road and (having 8 tubes on one tank) i save myself $240. at least.

[Dark]

you can use a light level meter to measure the intensity of your lights - i have not done this but i believe there is some form of photographic device that measures light levels.

you might have to put it in a plastic bag and drop it into your tank to get a proper reading though

[spooky]

The only problem with a light meter is that it won't tell you what the intensity at the photosynthetic wavelengths is (not without a filter at any rate).

As a footnote: A black-body at 14000K would have a peak wavelength at 200nm - well into the UV (visible light is roughly 750-400nm). It wouldn't be any good for plants, fish or passing humans.

[DiverJohn]

HI Snowman.

I have 3 really fat Simese Algae Eaters which cost me 10.95 ea @ the LFS. They are regarded as perhaps the only fish to control /eat BBA. BUT if you have major problems they aint going to help. When I combined an initial treatment of double dosed flourish excel to knock the BBA back the SAE can keep it under control. I did this about 4 months ago and have had no problems since, but continue to dose with flourish @ the recommended rates for the plants.

Lights: After doing alot of reading I dropped my lights back to 9 hours a day for a week while double dosing with flourish.

Kelvins: From experience you may or may not find some one at an electrical wholesaler that knows what kelvins are - "Who??"

If you run into dificulty finding something, I am running "Osram Biolux 965" these are available @ Rexell, but are a special order item. I have also ordered some "Osram Fluora" tubes and will be combining them with the Biolux, so will see how they go.. My current tubes are approx 6 months old so they whole lot is getting changed at the same time.

Seing as this is the technical section I downloaded these images from the osram site ( http://www.osram.com ) they show the "spectral power distribution" of the tubes. The osram documentation actually says the Biolux is a 6500K tube.

You could compare these to the 3000K Warm White, and the 4000K Cool White. These are quite high in the green part of the spectrum, which is good for Algae , not so good for you.

HTH, Good luck.

John