# Low light lighting



## flocci (May 3, 2007)

I have a fish only 30g tank that I've been running for about 8 months. I've always wanted to grow some plants, but I've only had the weak lighting from the basic hood that came with my tank.

I am considering buying new lights so that I can add plants to my tank. After reading various websites and forums, I think I would like to have a low to medium light tank, with around 2.5-3 Watts per gallon. Of course WPG does not appear to be the best way to measure lighting, so I was hoping I might get some advice about how much light and what type of fixture to get.

My initial plan was to get a the Current Satellite 1x65 Watt Compact Fluorescent. However, would T5 be better? I'm not sure I'm willing to spend the money on a Tek fixture, which may also be too much light. The Current Nova Extreme has a 2x24 Watt set up, but is that enough light for what I want to do? (Although both examples are Current, I'm not overly concerned about the manufacturer)

From a pure WPG measure neither of these fixtures are even providing 2 WPG, but does their greater efficiency make up for this?

Thanks for any help you can provide. I have been reading the forum, but most of posts seem to focus on much higher light and larger tanks.


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## trenac (Jul 16, 2004)

On my 30 gallon tank I have a 1x96 watt Coralife fixture which provides 3.2 wpg, a little more since these are power compact bulbs. I can grow almost any plant along with a nice carpet of Dwarf hairgrass. 

Since you want a low-medium light tank I would go with less wattage. The 65 watt fixture would work for your wants (2.16 wpg), being more on the low light side. But with PC bulbs you get more bang, so growing medium light plants should be no problem. 

I think in the T-5 bulbs, that the number has to do with the size of the bulb. With the smaller the number the smaller the bulb and the higher the number the larger the bulb. These are high output bulbs, so they will have more bang then a normal flourescent bulb. I couldn't tell what the difference would be between the PC & HO though.


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## K20A2 (Aug 12, 2006)

Depending on how low you want to go you could try this fixture. Its a normal output T5 fixture with a fairly reasonable price. http://www.bigalsonline.com/BigAlsU...6/cl0/coralifefwt5aqualightdoublestriplight36

I'm using this on my 30G along with an AH supply retro kit. Now, I like a bit more light and faster growth but if you wanted to use this fixture you wouldn't have to inject CO2 and could keep it chill on the fert dosing. There are a decent number of plants that will grow under this amount of light just not that fast. Oh, also the mix of the 'planta' bulb and the 6700K look nice as well.


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## flocci (May 3, 2007)

K20A2,

How wide is your tank? My 30 gallon is 30 inches wide. How do you have your 36" wide fixture setup? Did you suspend it, or do you have 3 inches hanging over each end?

Thanks


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## K20A2 (Aug 12, 2006)

My 30G is 36x12x16, perhaps it is a long version. Your tank is probably taller then mine but not as long. 

But, your still in luck if your interested in one of these lights. Just check out the other coralife T5 fixtures on bigalsonline. They make a 30" long fixture that would sit evenly on your tank.


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## ruki (Jul 4, 2006)

trenac said:


> I think in the T-5 bulbs, that the number has to do with the size of the bulb.


The T size is the tube diameter in eights of an inch. T5's are something like optimized T8's that have been developed in Europe. Just as T8's are like optimized T12's.



> With the smaller the number the smaller the bulb and the higher the number the larger the bulb. These are high output bulbs, so they will have more bang then a normal flourescent bulb. I couldn't tell what the difference would be between the PC & HO though.


Power Compact is similar to T5 HO. But there is variations in shapes, ballasts and drive current with Power Compact so this makes it difficult to directly compare against T5 HO.

The main difference between Power Compact and T5 HO is that Power Compace is great for generating lots of light in a very small space while if you have enough space the T5 HO linear bulbs with a good reflector send much more light into the tank (watts per gallon that get sent down into the tank are much higher and the photons generated per watt are probably a bit higher as well.)

For a low light tank two feet accross or longer, two linear tubes accriss the top will provide a good medium light. I use one plant bulb and one 6500K bulb. T12, T8 and T5 will put out about the same amount of light, but the watts per gallon number will be different since the smaller tubes are more efficient at producing light from supplied electricity.


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## trenac (Jul 16, 2004)

Thanks for clearing that up, Ruki


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