Cleaning scale tips please

[earhtmother]

Other than soaking in/with vinegar & elbow grease any tips for cleaning equipment that goes IN the aquarium

 

[Delapool]

Probably pretty well known but I always clean filter impellors - they don't really get scale (or mine don't), but I find a rub with a cloth helps (sometimes in mine they block up and stop). Might be just unlucky as the CO2 injection also has gear with impellors so running impellors for 4 or 5 things in the tank.