The aqua turn won a Prince Charles award for somthing or another many years ago?
I have installed & sold probably 50- 60 in the last twenty years, mostly for Kio pond installations but I have used & endorsed their use for fish tank use too.
I have installed several in commercial enterprises over the years, including several in huge marine tanks.
Virtually silent in operation
It is just a simple piece of injection molding that allows the use of a very high production pump to be used in many different circumstances including salt water.
My plant tank that uses the Grundfos is only about 200lr & it has a sump that makes full use of the pump, it powers a trickle filter & the main return all on the lowest setting (about 40w i think) but it is very useful to up the power on occasions!