T5HO & low light tank

V

vthokie

JW
Sep 29, 2005
44
0
6
South Carolina, USA
Would 2 54-watt T5HO bulbs over a 75 gallon tank be considered low light?

I've read that you can multiply the standard wpg calculation by 1.4 to get T5HP wpg. I'm not sure if this is true, but by doing this the 2 54-watt bulbs would be about the same as 2 wpg of non-T5HO lighting.

I'd like to avoid having to add CO2.

Thanks!
 
Watts are watts. You still have only 108watts over your 75gal.

You still at only 1.4 watts per gal.

CO2 is always nice to add, but at this low you can do without it.
 
Yeah, it's still low or low/medium light. t5s are more efficient than t12s for sure, and a bit more efficient than t8s but you will still have rather modest lighting. I think you could grow any low light plant, along with vals, ludwigia, swords, and the like. No need for CO2 if you want to keep it simple.
 
worst case scenario a small diy co2 just to keep algae at bay may do you wonders. if you can adjust the height of your lights you more than likely will not need it at all imo.
 
This is a never ending question that I deal with everyday with my customers. The following is the conclusion I have come up with on the whole lighting and watts per gallon rule.

In my opinion watts are watts but watts are not what the output of a light bulb is. Watts is how much power a light bulb will use. The light output (Lumens) is what you need to look at when figuring how much light your tank has. I.E. A 26 watt compact florescent bulb has a light output equivalent to a 100 watt light bulb. The light intensity of your average florescent light is not in any way close to the intensity of a t5ho light. Today's light fixtures use low wattage and have high intensity light output. 2 t5ho 54 watt bulbs over a 75 I would consider high light. I am currently running a 75 gallon with one t5ho 54 watt bulb and I am successfully growing many plants that would be considered high light plants. Along with 103 other planted tanks that I have experimented with just about every kind of light available and come to the conclusion that the light output intensity (Lumens) is the determining factor when choosing a bulb. The watts per gallon rule I feel is inadequate today due to the fact that there are too many factors that determine which light is suitable. I.E. Tank height, Light Fixture Output Intensity.
 
The watts per gallon rule doesn't really apply to t5 HO lights. t5 HO lights with single reflectors are 3-5 times more intense than PC light. So I don't think it's low light.
 
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I can't argue with Sweet Aquatic's personal experience but my understanding is t5s produce more lumens per watt (83) than t5ho (71). On the other hand the ho bulbs have more ability to penetrate deep into the tank, so that would be a big factor I think if you have a large aquarium.
I used to have a good link comparing lumens and watts of various types of bulbs. I did come up with this post from another forum:

http://www.plantedtank.net/forums/lighting/25638-t5-t5ho-vs-compact-fluorescent-power.html
 
I use 1.8 w/gal on T5 on a 120 Gal tank and it's plenty.
I use CO2 and adding it will help reduce the intensity required.
In other words, adding CO2 will always help.

Regards,
Tom Barr
 
Looking at the charts, the standard T5s may produce more lumens per watt, but the T5HOs produce more overall lumens which provides that deeper penetration you were referring to. Just thought I'd point that out to the folks who might glance at that and think the standard T5s are brighter the the T5HOs. They are simply just more efficient for their size.
 
i got the same set up my plants are doing great with out co2 2x54 current usa over my 75 gallon low light plants are doing good i put fertilizer tabelets in my sand every 4 months no problems
 
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