I have been looking at many different brands f clarifiers for my 4000+
gal pond. Some of the more expensive larger units seem to specify
horizonal or vertical, but most basic units for 4000 gal ponds don't
reference the preferred orientation or the size of the units. I am
trying to figure where or how I would back fit a UV into my existing
some what cramped plumbing. Does it matter if they stand up or lie
down as long as the air gets out of them.

Also, I live in Minnesota, so I assume I would have to remove this
unit and take it indoors during Winter.