Beamsworks are reasonable lights .I use them on many of my tanks .
I like using 2 @ 36 but they do offer 72 inch units.
I like the DA FSPEC myself and even use a $5 ebay dimmer with mine ..
https://www.amazon.com/BeamsWork-FSP.../dp/B01LFF07EC
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1