# T5 vs PC lighting for 20G



## Harry Muscle (Oct 17, 2007)

I'm doing some homework in preparation for maybe getting a 20G open top tank (the actual tank dimensions would be aprox. 24x14x16). So far the choices for lighting seem to be:

28W PC (Aqualight 20" fixture) - aprox. 2100 lumen
24W T5HO (Aqualight 24" or Hagen T5HO Glo 24" fixture) - aprox. 2100 lumen
36W PC (Aqualight 24" fixture) - aprox 2700 lumen
48W T5HO (Aqualight 24" or Nova Exteme 24" fixture) - aprox. 4200 lumen

I'm hoping to get as much light as I can without needing to use Excel (since it kills my vals and I think also mini pellia) nor do I want to use CO2. So basically I'm looking for medium light ... ish.

The plan would be to have the water about 2" below the top of the tank (to prevent jumpers) and have the light elevated on legs (I'm not 100% how much height that will add, but I'm guessing 2" to 3").

I've done some lumen per square inch calculations since they are way more accurate than the old and outdated watts per gallon idea. My old 55G tank which had two 4 foot 32W T8 bulbs over it had about 10 lumen per square inch (LSI). It grew most but not all plants and I would have considered it to be low light bordering on medium.

That means that the 48W T5HO fixture would give me about 12.5 LSI, which is about 25% more light ... I just don't know if that is too much light and would require CO2 and/or Excel (btw, I dose fertilizer regularly, so that's not a problem). Hence I'm looking for opinions. Also lumen per square inch doesn't trully tell the whole story and something is telling me that a 48W T5HO fixture over a 20G would be way more light than my calculations are telling me.

So if you were setting up a 20G open top tank and wanted as much light as possible without needing Excel or CO2, which light would you choose from the above list ... or is there maybe another light that you can recommend that's not mentioned.

Thanks,
Harry

P.S. There's also the Aqualight 24" T5 Normal Output fixture, which has two 14W T5 bulbs that should be added to the list.


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## tom855 (Feb 5, 2006)

I'd have to guess that T5 HO will be more the way "of the future." Bulbs are easy to find and they put out lots of light. 

I've had great luck with Nova fixtures, and some of them really pump out the light. I think the biggest variable in your selection is how much light it try coming out of those fixtures (I'm talking reflectors now) not just the amount produced by a bulb. There is a big variation between products, even in the Nova line. However, your gut is right. HO T5 fixtures with good reflectors really can light things up.

IMHO you might want to consider the idea of using Excel. It's much easier to control than CO2, not that expensive, and might give you some wiggle room on picking out the exact right fixture.

Tom


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## Izzy (Jun 4, 2006)

The 48w T5ho would be my first choice. The bulbs last longer, are getting less expensive and easier to find. They could run for a shorter photo period with better saturation. You have the option to try co2 in the future.

Individual reflectors are best, they will produce more useable light and are more economical to run. The other key is fresh quality bulbs and balancing the ferts not allowing algae a foothold.

I have the salt water 36" 2x39w Aqualight and like it very much over my 46 bow. The 6700 and Actinic coralife bulbs are oem. I'm trying the Actinic to see if my red plants get redder. Some have said the Actinic causes algae, but i'm still experimenting. If after a few more months I don't see anything wonderful they will both be replaced by Giesemann Aquaflora and Midday. 

You are correct: vals and pellia are not good candidates for excel. What other plant are you considering for this setup?


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## fishyjoe24 (May 18, 2010)

may I add on to this as I have the same questions, should I use t5's or pc bulbs over a 20's /2 -20 gallons.


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## tom855 (Feb 5, 2006)

I would strongly encourage you to use the HO T5s. They are much, much cooler and without a doubt the trend going forward. They also are often usable without a fan which is wonderful. The bulb selection is better as well.

No question. Go HO T5 if you are making an investment in lighting.

Tom


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## fishyjoe24 (May 18, 2010)

tom855 said:


> I would strongly encourage you to use the HO T5s. They are much, much cooler and without a doubt the trend going forward. They also are often usable without a fan which is wonderful. The bulb selection is better as well.
> 
> No question. Go HO T5 if you are making an investment in lighting.
> 
> Tom


I have 2x96 pc bulbs over my 55g and to me they just put out to much heat and light. how many t5 high out put bulbs will i need to by for high light plants. because i saw some 48 inch 6,700k coral lifes on clearance at petco for 6.99 a piece, even at 19.99 at other places that will be alot cheaper then 59.-79.99 for the pc bulbs i've been buying. thanks.


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## tom855 (Feb 5, 2006)

The 48" HOT5s are 54W each. I would suspect a 4 bulb fixture would provide even more light than your current setup. For MY money I'd buy two 2-bulb fixtures. You can cover more of the top of the tank with two fixtures AND THERE IS NO FAN. You haven't lived until you've lived without a fan on your light. Having two fixtures would also allow you to reduce the photoperiod if you decide that four bulbs put out a bit too much light.

Hope that helps!

Tom


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## fishyjoe24 (May 18, 2010)

tom855 said:


> The 48" HOT5s are 54W each. I would suspect a 4 bulb fixture would provide even more light than your current setup. For MY money I'd buy two 2-bulb fixtures. You can cover more of the top of the tank with two fixtures AND THERE IS NO FAN. You haven't lived until you've lived without a fan on your light. Having two fixtures would also allow you to reduce the photoperiod if you decide that four bulbs put out a bit too much light.
> 
> Hope that helps!
> 
> Tom


thanks now to just find a place that has good ballast, and bulbs that will fit in my canopy.


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## tom855 (Feb 5, 2006)

Can't help you with the DIY version. I've only bought the fixtures. Seems to me I've seen the parts at PetSolutions and Dr. Fosters Smith though.

Good luck!

Tom


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