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Warm White lights

PostPosted: Sun Feb 08, 2009 5:16 pm
by Don Trinko
Are warm white lights useful for growing plants?
I will have a 14 watt 10k and 2 13 watt warm white t5's on a 20h. Will this be enough for most plants? Would I be better off to find cool white lamps? Thanks; Don T.

Re: Warm White lights

PostPosted: Sun Feb 08, 2009 7:33 pm
by kb46
Generally, "cool daylight" is the description you should look for for plant bulbs if you can't find a Kelvin rating. If you can find a Kelvin rating 6500K - 10000K is the right range for plants.

I've definitely noticed a difference in plant growth swapping out warm bulbs for cool ones. The change was almost instant - within a week there was really noticeable improvement. But that was with energy-saving bulbs not T5's.


Re: Warm White lights

PostPosted: Sun Feb 08, 2009 8:34 pm
by montanahh
Give it a try. Easy enough to switch out the bulbs!!

Re: Warm White lights

PostPosted: Mon Feb 09, 2009 11:07 am
by freshfish
Holy cow that's a lot of light over a 20gal tank, especially with T5 fixtures! You should be able to grow just about anything with only one of those fixtures and good CO2.

You're definitely going to have to set up CO2 on this tank and a heavy, balanced fert regime for the plants to have any hope of keeping up with that much light. Otherwise, you'll end up with an algae farm.

As far as color temperature of the bulbs, that's really more a matter of your own personal taste. Most bulbs between 5000-10000k will support FW plant growth just fine, and I'm not sure that anyone has actually scientifically proven a difference between bulbs.