First off I live in Central Minnesota in Zone 4A. I have pond that now
holds 5000 gallons minimum and gets full sun during the summer. It has a
surface diameter of 20' and is 26" deep. The pump currently flows 1800 GPH+.
I used a five gallon bucket but at that rate it is a little hard to time. I
would say it gets over 8 hours and close to 12 hours of full sun through out
the summer depends on the time of year.
It will freeze our during the winter so it will be emptied and the
filters will die and loose all bacteria. I will have to start over again
next spring spiking the filter system with gravel from there indoor pond. I
do not want to create a green house and try heating it or spend next year
paying off the electric bill from trying to keep the pond from freezing this
winter.
Knowing I will have to start over in the spring and I would like clear
water and not an algae bloom because the plants will only cover say 10% of
the pond what size UV filter would you get? Currently I do not have string
algae or anything like that the water is just green from the small suspended
algae. I have been reading ratings and they vary depending brand and the
person selling it even on the same UV light. I am running the output split
to two sources so I can run around 900 gph through a single clarifier or
1800 gph through two. Or get a single large one for both lines.