Mag 18 cavatating?

[andresont]

I used Mag pumps myself for long time and they are very reliable, however noise was always present.
It will quiet down somewhat in a few weeks when slime grow on the inner parts and impeller.
Also you can use some sort of "niose dumper" like rubber foam or try to suspend it (Mag18 is very heavy though), i use to suspend Mag9.
Eheim is pump of my choice now, just because they a lot more quiet.

Bubles will clear up as well when bacteria slime grows on tank panels.
Unless you have air coming from somwhere else.