Hi,
I have to put in another vote for the AquaClear Powerheads.
Back in the 70's, I had a salt tank that ran with ug and some AquaClear Powerheads, skimmer etc. I don't remember what model they were, but they were about the size of my fist, or just smaller. I have small hands, so I'm thinking a 50 (70?) or so. I got out of that phaze of fish addiction, got married, moved to WA, divorced came back home and found them still in a box in Father's workshop. They cooked out there in the AZ heat for a number of years and I used it off an on for one thing or another and still ran fine. Somewhere along the line I loaned one out and lost it, so one left. The heat started to get to the plastic and the little cone started to crack in the 90's. About that time, I used it in reverse to drain an 8,000 gal. above ground pool. It took time, but not a problem. Ran like a champ.
Coupld of years ago I got a fly up my nose and gave a bunch of fish stuff to Goodwill. It was in the box. Cone at the end was gone, but it still ran.
Hetep