That's ok, I pretty much heard all I need to hear
& I think where all on the same page when it comes to Eheim & Fluval anyway so can't see it turning into a debate. Personally I think the only thing we should be debating is the price of these things, it's a bucket with a pump on it & they add a new snap lock doodad to it, call it new technology & charge a fortune for them. It's BS.Don't mean too double post here but my other half was nagging me & I wanted to make a couple of points here too. The fact your Dovii are swimming & eating more is probably testament too the water movement the FX provides, they are obviously happier. One thing I think is a bogus gimmick with the FX is the stop start, no other canister needs this feature & it just leads to problems like your experiencing. Just my opinion.
I actually didn't know that eheim do that deliberately, but now you've explained it, it makes sense, really good filters whatever way you look at it, just very pricey, and like I said IMO fx6 are better for big messy fish
