Paul Enterline wrote:
I have one of those "Drinkwell" water fountains for my two cats. The
water passes through a fiberglass/charcoal filter, then out a spout
into a dish, and is then recirculated. I have to add about quart of
water every three days.

Question: How long can I go without changing the water and the filter
and cleaning the unit?

I have had mine for over 2 years now.

The filter catches most of the floaties you might otherwise find in the
water. I refill mine with filtered water from the fridge.

Because the water is circulating and getting oxygenated it really
doesn't go stale or bad... you can likely get along fine with giving it
a scrub every week or so.

--
"Its the bugs that keep it running."
-Joe Canuck