bum it was 2nd hand! it did work when i tryed it in the sink!! but now wont! are they really really really needed to keep a marine setup good? anythink i can get insted of this???take it back if possible. They are so finnicky and hard to set up that the East of England Eheim rep had to phone Germany to help an lfs, it still failed. These are truly the bastard child of the Eheim family
no, they are definately not needed, especially with new methods such as berlin (bare bottom, loads of live rock, very high flow, heavy skimming) and hybrids (sanded, live rock, medium flow, water changes, moderate skimming).
What type of marine system do you want?
FO, FOWLR, Reef?