Lighting an Aquarium with PAR instead of Watts

[Bronco]

Hoppy thanks for taking the time to post this information.
Up until now I had been equating wattage with light intensity.
A mistake that would have cost me a lot of extra money that
I don't have. I just purchased a 30 inch tank so it falls into that
odd size bucket. I plan on using C02 and would like high light.
Would I better off using 2 aquatic life 2 bulb fixtures or just
get a 6 bulb Catalina fixture and hang it a little higher above the tank
to provide better coverage ? Thanks again for the informative post

[Bronco]

Sorry the tank is 24 inches deep

[Hoppy]

I'm not sure which light would be "best" for a high light 30 inch long tank. It depends a little on the front to back depth of the tank. If the tank is 12-14 inches front to back, a single light fixture should cover the substrate pretty well, but if it is 18" and more, I think two lights, or a single light, with two groups of two bulbs, with 7-9 inches between groups might work better. Or, if you want to hang the light above the tank, you could use a 24 inch long light with 4 bulbs. Then, there is always the LED option, too. You could also use a 4 bulb light, with two electric cords, and run the two front bulbs for half the photoperiod and the two back bulbs for the other half.

[Bronco]

Hoppy thanks for getting back to me. Sorry I just should
have given the complete dimensions of the tank right off
the bat. It's a cube that measures 30x30x24 so the light
will have to provide a lot of coverage. With this in mind would
any of the options you gave me for going the t5 route be
more favorable ?

[Hoppy]

A 30" x 30" footprint tank has to either use a light hanging high above the tank or a pair of lights sitting on the tank to get good coverage of the whole tank. That is a personal preference - you may like the appearance of a hanging light better, or want a light sitting on the glass top of a tank.

[Bronco]

Hoppy thanks again for the information

[gozzy]

Hi Hoppy

Could you take a look at my question a few posts back titled "Hagen Glo T5 Questions..... " please?

My tank size is 60cm x 30cm x 30cm.

Thanks

[Hoppy]

Originally Posted by gozzy

Hi I've been looking at the charts and info on here so first of all thanks for all the good information :-)

I have a Hagen Glo T5HO Lighting and have in there 1 x Dennerle Trocal T5 Longlife Special Plant + 1 Color Plus bulb.

I've only realised after reading this thread they are not HO bulbs but LO (i think) :-(

My tank size is 12" in height and judging by the chart if the light unit is sitting on top of the tank this will give me around 65 par? The chart doesn't say whether these are for HO or NO bulbs though?

Can someone tell me the best use for this fixture in terms of bulbs and height from substrate please? I am looking to be in the high light category.

Hagen Glo lights are T5HO lights, but with poor ballasts and just fair reflectors. You should get high light if it is mounted less than 16 inches from the substrate.

[fishyjoe24]

so according to this I would only get medium lighting with a coral-life t5 ho 2 bulb on a 27 cube 20x18x20 is this correct?

[Hoppy]

Originally Posted by fishyjoe24

so according to this I would only get medium lighting with a coral-life t5 ho 2 bulb on a 27 cube 20x18x20 is this correct?

That tank is only 20 inches long, so I assume you would use a 20 inch long light. I don't know anything about a Coralife 2 bulb T5HO 20 inch light, but it will give you less than 30 miicromols of PAR, which is low light. If the bulbs or ballast are worse than usual for Coralife, it might be as low as 20 micromols.

[fishyjoe24]

Originally Posted by Hoppy

That tank is only 20 inches long, so I assume you would use a 20 inch long light. I don't know anything about a Coralife 2 bulb T5HO 20 inch light, but it will give you less than 30 miicromols of PAR, which is low light. If the bulbs or ballast are worse than usual for Coralife, it might be as low as 20 micromols.

boo. might have to do a retro fit with some tek reflectors and gisemenn bulbs then.

or would this get me up to med high/high light. the aqua life will one work or will I need too.
http://www.marinedepot.com/AquaticLi...FIT54U-vi.html

[ThatGuyWithTheFish]

What do you mean by Catalina 1 bulb calculated? What wattage is it?

[Hoppy]

Originally Posted by fishyjoe24

boo. might have to do a retro fit with some tek reflectors and gisemenn bulbs then.

or would this get me up to med high/high light. the aqua life will one work or will I need too.
http://www.marinedepot.com/AquaticLi...FIT54U-vi.html

This is just a little better than a guess: I think you would get around 50-60 micromols of PAR right under that light. But, it would take two of them, one near the front and one near the back, to get good light coverage of the whole tank. That would be medium light or a bit more.

[Hoppy]

Originally Posted by ThatGuyWithTheFish

What do you mean by Catalina 1 bulb calculated? What wattage is it?

That should hold for 3-6 foot long bulbs, and possibly even for 2 foot long bulbs. The problem with guessing how much light one of the Catalina fixtures gives you is that they use more than one shape of reflector. Unless we have actual PAR data for the specific light you are interested in, this is just a crude estimate.

[ThatGuyWithTheFish]

I ask because I think my 30" 1 bulb T5HO might not be enough.