W/G Calculation...

[Lonewolfblue]

I'm getting a light strip that holds 4 compact bulbs, 65w each, 2 on each side of the 55G long, 48" wide. For calculating the w/g, would you use 65W/55G, 130W/55G, or 260W/55G? Not sure if you would use the total wattage or the maximum wattage of a single bulb.

Here's the setup:

http://cgi.ebay.com/ODYSSEA-48-260W...ryZ46314QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Thanks....

 

[Lonewolfblue]

Also, it comes with the actinics. I also ordered more bulbs to go in it. Will be using 2 12000k and 2 6700k bulbs, and no actinics.

 

[Jchillin]

Gotta use the 260, the calculation takes in the total wattage of all bulbs.

 

[Lonewolfblue]

ok, wasn't sure as it's 4 bulbs, 2 on each side of the tank. Thought it was going to be 130/55. But ok, will go with the 260. Now that I got that ordered and on the way, I can start researching CO2 systems and educating myself a bit more on that end. Hoping in a couple months I'll get another Walmart 55G with stand and make it a planted tank. Don't want a bigger tank as I'm saving for my real tank, anywhere from 180G-300G. But that will be about a year or so down the road.

 

[Jchillin]

I understand the thought...the individual bulbs are not lighting the entire tank. Even though the bulbs are "separate", since the tank itself is not divided, the overall light must be considered.

Would make an interesting experiment to see how much of the light from both sides are getting into the tank. There must be a mathematical equation out there somewhere...anyone?

 

[Lonewolfblue]

I was thinking 130+/55, as there's 2 bulbs per side. Would be over a bit in the middle, as you have all 4 bulbs, but on the ends of the tank, would be more like 130. Anyone else have any thoughts? Would be a good experiment. And thanks for the input Jchillin, and Merry Christmas.....

 

[Wizzard~Of~Ozz]

If you are considering the light to half the tank, then consider the volume to be half the tank aswell.. it's 260w. (the output of the fixture) / 55Gallons.

 

[Lonewolfblue]

Cool, thanks.....

 

[greenmaji]

little advace with the CF units.. the 4X55Watt units use the same ballasts as the 65's and sometimes there quite a bit cheaper..
you can replace your bulbs with 65w'ers when the 55's go out..
its just an option..

 

[Wizzard~Of~Ozz]

Greenmaji, I thought the bulbs came in 55/65w and were dependant on your ballast.. not the other way around.

 

[Lonewolfblue]

Isn't it true that you can put a 55W in a 65W setup, but not the other way around? At least that's what I heard. Can't go higher W bulb on a lower W ballast.

 

[Jchillin]

You can put a 65w in a 55g...that is the best way to go...you need at least 1wpg for plants.

If you put a 55w in a 65 gal, you will not have enough light (less than 1wpg).

 

[Lonewolfblue]

little advace with the CF units.. the 4X55Watt units use the same ballasts as the 65's and sometimes there quite a bit cheaper..
you can replace your bulbs with 65w'ers when the 55's go out..
its just an option..

Greenmaji, I thought the bulbs came in 55/65w and were dependant on your ballast.. not the other way around.

Isn't it true that you can put a 55W in a 65W setup, but not the other way around? At least that's what I heard. Can't go higher W bulb on a lower W ballast.

You can put a 65w in a 55g...that is the best way to go...you need at least 1wpg for plants.

If you put a 55w in a 65 gal, you will not have enough light (less than 1wpg).

I was just commenting on the lamp wattage and ballast scenerio. I know a 65W lamp can go on a 55G, no problem. My setup is going to be 260W on a 55G, that's 4.7W/G. Unless of course I use the actinics in 2 spots, then would cut it about in half.

 

[malkore]

No, Oz misunderstood Greenmagi...they are saying the same thing: that when the ballast that pushes 4x55watts gives out, that Lonewolf can put in a 4x65watt ballast for cheaper than another 4x55w, and then he'd get more power.

55w and 65w bulbs are interchangable. Some manufacturers flat out state the bulbs are 55/65w (look at www.hellolights.com bulb selection to see what I mean). Its only 10 watts. a 65w bulb might burn out a little sooner, but PC bulbs have a good 2 years of usefulness, so a couple months isn't much, especially if the extra 10w per bulb matters (40watts extra if we're talking about your 4x55w fixture)

 

[Wizzard~Of~Ozz]

Malkore, I don't think I misunderstood him, it is backwards.

you can replace your bulbs with 65w'ers when the 55's go out

the 4X55Watt units use the same ballasts as the 65's

They use the same bulbs, but have different ballasts, not the other way, like stating that VHO an NO are the same ballasts, just different bulbs.

 

[Lonewolfblue]

ok....

 

[malkore]

Oz,

you're right, I did misread Greenmaji's post..I thought he meant 65w ballast...but he does say bulbs.

I've still never found anything that definitively states 65w tubes are any different than 55w tubes...so even if you had a load sensing ballast, I suspect it'd still send the same wattage to each tube, so regardless of wattage listed for the bulb, the ballast would push the same 55watts out until you changed the ballast for a beefier one.

 

[Wizzard~Of~Ozz]

Correct, the 55/65 is the exact same bulb, if you buy one that specifically states 55w and put it in a 65w ballasted fixture it will run @ 65w (and it will work aswell, just at a slightly lesser lifespan, not that 2 years is really that short)

And yes, the 55w ballast will always put out 55w, even if you put a 96w bulb on it (probably wouldn't even fire). I didn't see a huge price difference between 65 and 55w fixtures.

 

[malkore]

65w fixtures and bulbs would run hotter too...something to keep in mind if you're already having large temp increases when the lights are on.
a small fan can usually remedy that though.

 

[Lonewolfblue]

The fixture does have 2 fans and legs on each end to attach to the aquarium, so it's not sitting on the aquarium.