We moved into new home in Fernandina about 3 years ago while new construction was still going on in our area.
Had Nova filters installed two years ago.
I just changed filters 3 weeks ago.
Here are pictures of the old ones (L-R) 20 micron, 10 micron & carbon. New ones are pure white.
I will change again in about 18 months now that new construction has moved a few more miles south of us.
I know usage is based on gallons (approx 25,000) not time.
We think it was well worth the $450.
Don