Originally Posted by Agnate80700
Dont get me wrong, I love my hydors I think they do exactly what I need em to. They just need to be placed so you get the most out of em.
I just replaced a MaxiJet 400 (100gph) with a Koralia 2 (600gph), and wanted to reiterate Agnate80700's point... the pumps are great, but don't expect to place them exactly where your old ph is that you're replacing. You'll need to rethink your placement for good current.
With the larger flow, I was able to move the Koralia onto the back wall (and hidden behind a rock) of the tank, and bounce the current off the side and then again off the front - kind of a double-bank shot. With the smaller MaxiJet I replaced, I had it on the side wall to start with. The end result was that I got a tad bit more current, but more dispersed... and was able to hide the ph behind a rock.
When looking at the gph
ratings of the Koralia's, don't get fooled. I really had to trust the guy at my LFS
that the 600gph Koralia wasn't as fierce as I was thinking, especially since I was looking at swapping it for a 100gph ph. Glad I listened to him because as Agnate mentioned, the flow is so much more dispersed, you can't really compare the gph
figures of these new pumps with the more directed flow of the MaxiJets. A more useful figure that ph manufacturers should give us is the water velocity at a point a couple inches in front of the output. That's really the number we're all interested in.