Hi, people do have elaborate pipework when needs must but the more bends in the pipe the more resistance there will be with possible implications on flow efficiency. Smooth curves if necessary are best, avoid elbows if possible or tight curves which could kink the hose.
Could you not have the heater inline but outside the cabinet, say behind/beside the tank before the return?
Everything i read was as long as the water flows according to the arrow and the unit is mounted vertically it will be ok. The instructions only mention vertical mounting and this is something to do with the thermostat switch which is why i put it upside down!
Hi, I also have a JBL filter which is rated at 1400lph and a hydor inline heater and I reckon that the way you have it set up will seriously restrict the flow. I see you have a hole at the rear of the filter which you might consider running your hoses through and fitting the heater and diffuser outside the cabinet??? Or see if the heater and diffuser will fit on top of the filter joined by very short pieces of hose??? Cheers.