Light required

pete · Posted: Mon Sep 25, 2006 6:17 pm Post subject: Light required

Hi I am thinking of getting a new tank a Regal 100 Aquarium 100 W x 40 D x 70 H so it is fairly deep 220 litres & it comes with 2 x 30w Twin Tube Reflector (not sure if that means 2x30w tubes or 4 think its 4x30w?) i read somewhere about light requirment for plants & im not to sure if this is the Min light requird for plants or would i have to add more (due to the depth)
Thanks
Pete

matt · Moderator

Hi Peter. Good question...

The general rule of thumb is that you should aim for 2+ watts per US gallon.

Your tank is about 60 US gallons, therefore, you would need 120 watts of light for a reasonablty flexible planted tank. By flexible, I mean that you should be able to grow plants that have "low" through to "medium", perhaps "high" light requirements.

Hope this helps.
_________________
My Planted Tank Journal

pete · Posted: Wed Sep 27, 2006 6:40 pm Post subject:

Thanks for that matt
I was looking at a Aquaone ar980 as well i looked on there site & found this "Improper lighting may lead to a range of health and other problems. It is possible to measure the intensity of light, but most fish keepers do not have the specialised equipment required to measure light intensity. Instead, they rely on wattage as an indicator. Some fish keepers have grown corals successfully by illuminating produces approximately 1-2W of light per litre of water, while many aquatic plant specialists have achieved notable success by providing their plants with a level of illumination equal to 1-2W per 2 l."
Now i am confused
they are talking 1-2w per litre if i got it right you would multply this by 3.78??
this tank also uses the T5 lights with 2x30w & 1x25w hardly enough light i would think 85w for 215lts (57us gallons) but the T5 lights are suposed to be better than normal tubes ? so does anyone know how to work out if this amount of light is high enough ie above 2w per usg
hope all this makes sense to somone??
Cheers
Pete

matt · Moderator

I can see why you're confused...

T5 are indeed brighter than their T8 equivalents by, I think, about 30%. So:

85 watts / 75 US gallons = 1.49 WPG

1.49 + 30% = 1.93 WPG.

That's how I'd work it through, although do check my guess at 30% brighter.

Cheers
_________________
My Planted Tank Journal