18000K 10000K?

[mycoolhoney]

how many K's do i need for a planted tank

[Smokin_Cache]

Re: 18000K 10000K?

From my research plants prefer 5000K to 6700K. Although the 9000K+ lights put out more light in the human visible spectrum they do not put out more total light than a comparable 5000K. We humans just see it that way.

I started my tank with 50/50 for about a week then came across some 10000K and I ran them for about 2 weeks. I then changed to 6700K and I could not believe the difference in plant growth. I can take the 6700K off and place the same amount of 10000K and can tell the difference in the amount of oxygen the plants are bubbling off. Its probably 25 to 40% less with the 10000K.

[HFBfounder]

Re: 18000K 10000K?

That is great info!

[mycoolhoney]

Re: 18000K 10000K?

thanks that was a big help now i can go buy my lights

[HFBfounder]

Re: 18000K 10000K?

To me the 5000K to 6700K do look kind of dingy though. That's why I think I'll sacrafice some growth for brightness. Or maybe I'll put in double lighting.  :think:

[Mzungu]

Re: 18000K 10000K?

I'm about to do an experiment when a shipment of power compact fixtures comes in the mail (off ebay). I agree that the 6700K can look kind of...yellowy-green, but plants do really well with it. In the fixtures that are on their way, which each have 2 PC bulbs, I plan on doing one 6700K and one 10000K. Hopefully it will make the light a bit crisper (for my viewing pleasure).

I have one tank with a 12000K on it, and I don't think I'll ever try going over 10000 again, yes the plants grow, but like Smokin said, there's a big difference when you use a 6700K.

They also make dual daylight bulbs, with a combo of 6700 and 10000, which I wish were more readily available.

[Smokin_Cache]

Re: 18000K 10000K?

That is my plan. At the moment I have 192w of 6700K over each side of my 125. Thats a total of 4ea 96w PC bulbs. I picked up 2ea. 10000K 96w PC yesterday that I am going to add in front of the bulbs already there. So each side will have 2ea 6700K rear and middle and 1ea 10000K at the front of the tank. That will be a final number of 4.6wpg. But that is scewed because of the 20 to 40% of the 10000 not bing used by the plants

[mycoolhoney]

Re: 18000K 10000K?

is there any diferance from the 6700K homedepot sales for $6 and the 6700K petsmart sales for almost $30

[armthehomeless]

Re: 18000K 10000K?

$24 - hehe

[armthehomeless]

Re: 18000K 10000K?

Seriously though, that is a good question. I always assumed that there wasn't... aside from the "brand" name. Two lights that emit the same color spectrum at the same Kelvin would seem equal to me. I honestly am not sure if there is a difference or not, but I have been using the lights from the hardware store for a couple years on planted tanks, and haven't had problems. I don't think it would be worth the price difference -even if the two light bulbs were not created equal.

[mycoolhoney]

Re: 18000K 10000K?

i just tried some T8 32w lights 48" they are less watts but they put out more lums

[Smokin_Cache]

Re: 18000K 10000K?

Well I added two more 96w 10,000K fixture in front of the four 96w 6,700K. Everything is the same ecept for the new lights. the 6,700K are in the exact same position. After I turned on the 10,000K my bubble trails have reduced in buble rate. Before I turn them on I had trail with less than a 1/4" between bubble now there is at least 2" between them. I am going to turn them (10,000K off and see if the bubble rate increase again. From what I can see at this moment though the addition of the 10s have slow the photo process somewhat.

[Mzungu]

Re: 18000K 10000K?

Interesting... Have you seen any difference since you turned them off?

[Smokin_Cache]

Re: 18000K 10000K?

I haven't had time to watch them. I plan on turning them off wehn I get home and see if I see a increase in the bubble rate.

[HFBfounder]

Re: 18000K 10000K?

weird. Do you think it might be a wattage draw problem?