# T8 Good for plants?



## Wasserpest (Jun 12, 2003)

Not sure what sort and size of tank we are talking about, but the lights that come with tanks are not meant for growing plants... even if they claim that.

T8's are a very economic way to add light, they also run very cool (efficient).

PC lights and T5's will get you more light for more money.

As for your other questions, it all depends what you can (and want to) do...


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## bharada (Mar 5, 2004)

Then again, looking back at Amano's first _Nature Aquarium World_ book (published in 1996), you'd see that all his tanks were lit by 20/30/40w NO fluorescent tubes. Granted, his tanks back then weren't the high-tech wonders they are today, but he still seemed able to produce some fine plant growth.


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## Momotaro (Feb 21, 2003)

Very true, Bill.

If I remember correctly, he used quite a few Crypts, Anubias and mosses at that time as well.

Mike


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## bharada (Mar 5, 2004)

Yeah, he definitely used a lot of low light plants in a great majority of those tanks. But he also did a few that featured a lot of stem plants...star grass, HM, Myrios...oh, and of course, gobs and gobs of Riccia.

Of course, he did a 48x40x30 stem plant tank and lit it with twenty 20w fluorescent tubes. :icon_lol:


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## TAF CAF (Jan 12, 2006)

Sounds good. I placed one light over a 20 gal, and it was a huge improvement over the light that came with it... but now I need to get glass hoods and mount them I guess.

Thanks for the comments!


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## TAF CAF (Jan 12, 2006)

Okay... more questions... maybe I should start a new thread, but will try here first.

I now have some acctual lights meant for fish tanks (got on super sale). 

Now I need to know if a 'Marine Glo' (wow is that thing BLUE!) would be any good for a planted tank together with a regular t8, or if it would be better to go with just the two regular t8s.


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## spypet (Sep 15, 2006)

blue "Marine" or "Actinic" are designed to penetrate your water to give light for live rock, softies and coral in a salt water aquarium. they are of little use in a freshwater planted tank.

try to focus more on the Kelvin rating on the bulb itself, not the diameter (T8 or T5). 6500-7200k may be best for red shift color plants, while 10,000k is good for all plants. special purple color enhancing bulbs don't help the plants more, they simply display fish and plant colors better for the human eye to enjoy.

I actually have Four T-5 bulbs; 2x 6700k, 1x 10,000k, and a purple "colormax" bulb.


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## Wasserpest (Jun 12, 2003)

Interesting, no day goes by without learning something new...


> try to focus more on the Kelvin rating on the bulb itself


I always thought that the Kelvin rating was pretty meaningless for plants, since it is just some color rating, which can not express the actual spectrum. I used to pay more attention to things like wattage, lumen, reflectors and such, but now I will really try to focus on Kelvin ratings.



> 6500-7200k may be best for red shift color plants


That is probably the most interesting thing for me... what are "red shift color plants"? Definitely some uncharted territory here.



> special purple color enhancing bulbs don't help the plants more, they simply display fish and plant colors better for the human eye to enjoy


That's a new one too... I blindly assumed that those pink/purple plant grow bulbs emitted a spectrum of light waves that tries to optimize the maximum absorption ranges for photosynthesis. So that's out the window...

Well I am sure glad we now have a true expert here at the Planted Tank. Welcome! :thumbsup:


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## TAF CAF (Jan 12, 2006)

Hummmm... have I opened a can of worms?

<< Taf ducks behind her hornwort >>


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## Wasserpest (Jun 12, 2003)

Just take EVERYTHING you read with a few grains of salt (K2SO4 works well too). :icon_roll


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## TAF CAF (Jan 12, 2006)

So would you think that the super blue 'Marine Glo' would do any good for the plants? If it penetrates the water to get all the way down to corals, would it do the same for the plants? Or is it just too far on the blue end to do any good?


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## Wasserpest (Jun 12, 2003)

I think Mr. Spy was spot-on with that one. :smile:


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## spypet (Sep 15, 2006)

I'm far from being an expert in anything.
All I have is 9 more Months of trail and error
and thousands of hours of reading ahead of you  

I'm sure some >2,000 post purist/moderator will chime in at any moment and answer your blue light question definitively.

my guess would be that plants want all colors of light accept green to maximize photosynthesis. so if all you are giving the plants is blue, you are depriving the plant cells from about two thirds of all the other visible spectrum it could be using.

then why not use white light in a salt tank... white simply won't penetrate as well as blue, possibly because the salt in the water diffuses light more than clear water would. blue, being a shorter thus finer wavelength is able to "wiggle" past all those sodium chloride molecules. Think of blue laser being a finer reading head on your DVD player, versus the old Red lasers on your CD player. again, that's only my educated guess.

wattage, lumen, reflectors all have to do with maximizing the amount of total light yield you are getting for the electricity you are paying for, but the quality of light, and it's usefulness to various plants and animals, has much more to do with it's Kelvin rating.

as for Kelvin helping encourage red shifting in plants, that is only one influence that bares noting. Phosphate levels also play a roll in the not just green color found in most aquatic plants.

I think high Kelvin bulbs like 15,000k-20,000k also penetrate better, but that is probably only an issue if your tank is deeper than 30" of freshwater. again, that's only an educated guess.

Kelvin rating is good for human beings too! Higher Kelvin rated fluorescents are often used in office spaces to make the lighting more comfortable for workers who must work long hours away from natural sunlight. the bulbs may be a bit more expensive, but are more than made up for in the value of productivity gained.


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## TAF CAF (Jan 12, 2006)

Very interesting.... so I will set aside the 'Marine Glo' and see if I can find a compairison on the Kelvin rating on the bulbs I have on hand.


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## TAF CAF (Jan 12, 2006)

Okay... here is what I found:

GE F17T8-SP41 

F17T8/741 (F17T8/SP41 GE) 17W T8 23 
1/8 75CRI 4100K FLUORESCENT 

Would this be 4100 Kelvin rating? Not much, right?

So does it mean in general that if I have only 77 watts on a 55 gallon tank, I should be going for as high in kelvin as I can?


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## Momotaro (Feb 21, 2003)

The Kelvin is going to determine how the light looks to _your_ eye, not to the plants.




> So does it mean in general that if I have only 77 watts on a 55 gallon tank, I should be going for as high in kelvin as I can?


No. The Kelvin is going to determine the color of the light, nothing more. It will play no real role in the situation mentioned.

Take a few minutes to read this:

http://www.plantedtank.net/forums/lighting/21052-comparison-lighting-types-lumens-watts.html

Rex's Lighting Guide

Spypet : What is a red shifting plant?


Mike


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## spypet (Sep 15, 2006)

TAF CAF, study this list of T8 bulbs from Coralife to see what's out there.

Energy Savers Unlimited | Coralife | ESU Reptile | Birdlife | Pondlife | Deep Ocean | A Worldwide Manufacturer of quality pet products

T8 10,000K Fluorescent Lamps 
T8 50/50 Fluorescent Lamps 
T8 ColorMax Fluorescent Lamps 
T8 Day-Max Fluorescent Lamps 
T8 Nutri Grow Plant Fluorescent Lamps 
T8 SpectraMax Fluorescent Lamps 
T8 Trichromatic Fluorescent Lamps

keep in mind if your fixture already has a reflector,
there is no need to get a bulb with one already built in.

ahhh, a wise moderator finally chimes in.
It is my belief that Kelvin does effect how plants utilize the light, not just how our eyes perceive it. red shift plants being ones that will display red in their leaves instead of just green. many such plants will grow green if the light and water chemistry are not right.


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## Momotaro (Feb 21, 2003)

Exactly what are we to glean from this list?

Mike


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## bharada (Mar 5, 2004)

That sounds like a standard cool white bulb. Not terrible, but not spectacular either.

The daylight T-8/T-12 bulbs on the market (Philips, GE, Verilux, etc...) are all in the 6500-6700K range. These are full spectrum bulbs, but have a distinct greenish tint to them...at least to my eye.

Also available is the GE AquaRay bulb. This is the famous (infamous) 9325K bulb that folks either love or hate for its pink/purple hue. One thing's for sure, the plants love them. This bulb can sometimes be found at Wal-Mart both in the "pet" and lighting departments. These are also OEM'd by All-Glass and can be purchased at places like Big Al's or Drs Foster and Smith.

Finally there are the tubes by Hagen, ZooMed, CoraLife, etc. These are typically sold only by pet stores so your best prices will be online from places like Big Al's.


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## bharada (Mar 5, 2004)

I should add that for most, the bulb selection can be culled down to 6500/6700K (daylight),8800K, 9325K, or 10000K varieties.

The 8800K may be the most difficult to find in a NO fluorescent tube. However, I find it to be the most appealing light as it's is a crisper white than the 6500/6700 (no green tint), but not as blindingly white as a 10000K (or higher) bulb can be.


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## Urkevitz (Jan 12, 2004)

I have had my best luck with T-8 bulbs. My favorite bulbs are the Phillips Daylight Deluxe from lowes, 6500k and they sell for about $6 for two.


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## Momotaro (Feb 21, 2003)

> I should add that for most, the bulb selection can be culled down to 6500/6700K (daylight),8800K, 9325K, or 10000K varieties.


What makes you prefer those bulbs, Bill?

Mike


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## TAF CAF (Jan 12, 2006)

Okay... Rex's really clarified a lot, thought the first link just makes my eyes go fuzzy... don't know at all what it is talking about.

So to sum it all up.... I am woefully under-lit, but still much better than the 30 watts that orrigionally came with the tank. Also should be looking to replace the bulbs I have with a bit higher in the K since the ones in there are only 4100, but not really nessesary to go any above 10000.

I am thinking 'red shifting plants' are those that start to turn red/pink in the leaves when they get good enough light. Am I right?


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## bharada (Mar 5, 2004)

Momotaro said:


> What makes you prefer those bulbs, Bill?
> 
> Mike


It's not so much a preference, but a quick list that a newbie can use to buy a bulb without too much thought, as all will work well over a planted tank. And all of them (except for the 9325) are fairly neutral in regards to color shifting.

Now my preference for the 8800K bulbs is based on side-by-side comparisons against 6500, 9325, and 10000K tubes. It is the bulb I would get for my TEK fixture if it only came in 54W T-5 size.


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## triple red (May 27, 2005)

bharada said:


> Also available is the GE AquaRay bulb. This is the famous (infamous) 9325K bulb that folks either love or hate for its pink/purple hue. One thing's for sure, the plants love them. This bulb can sometimes be found at Wal-Mart both in the "pet" and lighting departments.


i always thought the all glass NOF bulbs were 8000 k
i replaced my aga tubes with aqa rays...totally different All-Glass Aquarium - Aquarium Lighting
i could be wrong....my gf likes to point that out all the time


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## bharada (Mar 5, 2004)

triple red said:


> i always thought the all glass NOF bulbs were 8000 k
> i replaced my aga tubes with aqa rays...totally different All-Glass Aquarium - Aquarium Lighting
> i could be wrong....my gf likes to point that out all the time


Actually, i think you're right. They switched to 8000K sometime last year. But prior to that they were selling the 9325K bulbs with their fixtures.


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