[CobraFnD]

I went to a store today, and they had a 24" VHO single bulb light on sale, and I was looking at it, and it was only 24 Watt... my 48" reg. florescent light is 40 watt... I thought that they were supposed to be way brighter... Does watts have nothing to do with it?

 

[petlover516]

it also matters on what kind of bulb in general as well as the k rating.

 

[CobraFnD]

well the reason I asked, is because I was going to put the light on a FW tank... for plants... It recommends so many watts per gallon... so if the watts are pretty much the same, I really do not need VHO lights I would guess.

 

[JIM]

Youre comparing a 24" bulb to a 48" bulb, the bigger the bulb the more wattage. Please visit the below link for an explanation

VHO Fluorescent Lighting

 

[AZDesertRat]

A 48" VHO bulb is 110 watts compared to the normal at 40 watts. A normal 24" bulb is only 20 watts compared to the VHO at 75 watts. They must have had the wrong bulb in it or were misrepresenting it as 24 watts is not VHO but is called HO.

 

[CobraFnD]

Hmmm... Now that I think about it, it may have been a HO... I know it was T5, and thought that it was VHO... I was using the 48 to compare, because I figured if 48 was 40, then 24 would be about 20, and this T5, HO or VHO was only 24 watt... Had to have been HO... it was 100 bucks on sale for 50.

 

[CobraFnD]

It was an HO... I just checked... that makes more since.

 

[Dmaaaaax]

T5s reguardless of their wattage also have more lumens...or higher penetration power getting to the bottom of the tank. If you measure your light with a lux meter, chances are that that lower wattage T5 will stil have more light at the bottom of a tank than your standard 40w.

The K rating or Kelvin is the temperature. This is an idication of the spectrum that your bulb is putting out. Most fresh water plants want full spectrum, so anything betwee 6700K (yellowish) to 10,000 (white) is fine.