Just spent some time on their website but am confused as to which one I want/need. I have a 72 gallon display tank with a 20 gallon sump, but it seems my only options are for treating 70 gallons, 75 gallons, or then up to 150 gallons?This is one of the TOP companies producing UV sterilizers, look into them skimping on a UV is a COMPLETE waste of money, they have sizing documentation on their website.
https://aquaultraviolet.com/
Sue