# T5HO bulbs



## Modo (Oct 9, 2012)

Just want to get an idea of what kind of bulbs do you guys used for your planted tanks to help plant growth. I have a 36" 78 watt total output. Thanks.


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## pyrrolin (Jan 11, 2012)

6500 k or 6700 k is all I wil buy


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## Newobsession (Nov 17, 2010)

generally 6700k-10,000k and have had luck with the rose coloured ones aimed at planted tanks. Although I must admit a I can get 6500k dirt cheap at work so for the 200k difference a few have found their way into my planted fixtures


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## Modo (Oct 9, 2012)

I think I have a 6700k and a rose colour one came with my light. But haven't had any luck growing my hairgrass. Wondering if 2 6700k would be a big difference.


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## pyrrolin (Jan 11, 2012)

Bulbs are usually only effective for plants for a year max. If your bulbs get old, you can see the difference in your plant growth


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## Modo (Oct 9, 2012)

I only have the light since December. Hasn't been that long. May try to switch over to 2 6700k.


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## Newobsession (Nov 17, 2010)

what size is your tank? it could be light penetratration rather than colour that's the problem. Also, root tabs help. What exactly do you mean when you say you haven't had luch with hair grass? It dies or just doesn't spread?


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## pyrrolin (Jan 11, 2012)

6500 or 6700, depends on the brand, they are both basically the same


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## BillD (Jun 5, 2006)

I prefer 5000K tubes for plant growth and overall more natural appearance. However, there are other factors that need to be considered. The colour temp of a tube won't necessarily tell you how well it will grow plants. The individual spectrum of the tube will determine that by how much of the light is in the two blue and red spectrum areas, at the right wave length. As well appearance will be influenced greatly by the Colour Rendition Index (CRI), with higher being better. All tubes of a certain colour temp, even from the same manufacturer are not equal. As an example Philips has 5000K tubes that have CRIs ranging from 82 to about 94 or 96.
As to how long they will grow plants, it has always been stated that with normal colour shift and power drop, flourescents are good for plant growth for about 6 months. I have some Philips Ultravision 5000K, tubes that were given to me after they had been used for 6 months in an office building. They are still growing plants after 3 years of 12 hour a day use.


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## Fishfur (Mar 4, 2012)

Fwiw, I like the Phillips Daylight tubes, which are 6500 K, I believe. I don't know what the CRI is, that's new to me, and thanks for the mention BillD, but they have given outstanding results for my light garden, which is where I use them. I also use their Daylight version 6500 K spiral bulbs, over my tanks, until such time as I can afford a nicer fixture that uses tubes. Meantime, the spirals grow most things I want to grow, in a tank 18 inches deep.


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## BillD (Jun 5, 2006)

I have some 6500K tubes also, but I don't really like the way they make the green plants look. The colour of the plants under the 5000K looks more natural.The problem i have here is that the 6500K recommendation, is starting to take on a life of it's own. So called "daylight " tubes in the 6500K range aren't really akin to daylight. The colour temp of sunlight at noon at the equator is around 5500K. 6500K would be closer to angled light typical of morning and afternoon. I personally find the 6500K tubes are already looking blue. My own personal experience is that 5000K outperform 6500K in plant growth. That is my experience, repeated over time. It may have to do more with the specific tubes than the colour temp. So, go with the one you like or mix them. Whenever possible opt for a tube with a high CRI, which is usually printed on the sleeve or right on the tube.


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