I have two of the w3500 pumps in my pond. These replaced the flimsy Aquascape garbage installed by the pond contractor.
These run 24/7 year round and have done so for around 3 years with no
inherent problems. I just pulled them out to clean off accumulated gunk
at the intakes and took the intake housing off to clean impellers with a
toothbrush. Easy, quick maintenance.
I looked this page up in anticipation of having to replace one or both. Cleaning them up restored them back to full flow.
If/when i need replacements I hope Amazon has them in stock.
I have had my stream and pond in my small but very enjoyable back yard
for over six years. Prior to that I had two ponds in the previous home
for nearly 15 years. By far, this is the best stream flow I have ever
attained. Operation is flawless, cascades and waterfalls are
consistently full creating a wonderful sound. Loud enough to hear soft
enough to not intrude. Shipping was prompt with no hiccups or damage.
Would do it again.