[jeffkrol]

One word of caution Re: the 1W model. It uses an odd 21V power supply. Thought 15V was bad...
Main failure point of all these type lights is the power supply. 15V can be found on eeeek bay.. 21V not so much.
There are voltage adj. power supplies out there though at reasonable prices..
Just an FYI..

Oh and 72" models are available..so I assume your tank is 72"..
You would only need, at most, 2.
Might want to go "upscale" w/ the Beamswork quad 3w... Lensing helps for deeper tanks..
But get the 6500k model, unless you like blue..
https://www.amazon.com/Green-Element-Aquarium-Light-Fixture/dp/B00AT3T28Y

 

[jeffkrol]

I looked at the 3 watt ones but figured with the tank being 6'x2'x2' the 3 would give better coverage, and if 1 were to fail I could get a replacement and not be completly down.

good plan but the "big-uns" have dual power supplies..so unlikely to fail on both sides..
9" wide and 90 degree lenses are removable to get 120...........

W/ some DIY diodes are replaceable "fairly" easily.
Downside.. Less efficient..and would be a fix vs replacement..
You will probably get more overall PAR w/ 2 1W units..

Lumen rating 15000 3W.... 16000 2-1W.
$280 vs $240...
1w sleeker builds are nicer to look at..

sorry just throwing some comparisons out there to consider..

another advantage to the 1W is you can have one of those and 1 fspec w/ the colored LED's..
should give better color rendering overall..
https://www.amazon.com/dp/B01LFF07EC/ref=twister_B01LFF08QO?_encoding=UTF8&psc=1
Lumen output between this and the 1w is fairly equivalent.

bad thing about any of the above is no easy "dim" hack .. Well manual ones at 6A are "close" and should be w/in spec in reality..