I've got a FX5 on my 2m river tank with the intake at one end and a home made spraybar at the other. The spray bar points upwards. I've added 3 tunze 6025's, the first one is under the spray bar and points across the rocks. The other two are halfway down the tank, one pointing upwards and one downwards across the rocks. I've also got two internal filters near the intake which aerate the surface.
The whole setup give areas of fast current and slow patches, and most importantly a lot of surface agitation.
My other hillstream tank is 3ft with a Aquis 2200, the intake is at one end and the spray bar is at the other. The spray bar has one section agitating the surface and another spraying across the glass at the back. It also has a seio on the spraybar end which is directed at the glass at the front of the tank I've recently added a fluval 304 to the intake end to create more surface agitation.
I find that the hillstream loaches love to sit in the powerhead and spraybar flow on the rocks and on the glass. In both tanks the tiger hillstream loaches have bred.