Which angles to set up 2 powerful canisters

[SandNukka15]

Hey guys so I currently have a ehiem 2262 and an ehiem 2217 on my 180 with the ehiem 2262 intake on left side of the tank and the right side has the return and also both the intake and return for the ehiem 2217. I'll be adding a fx4 today since I got a good deal and picked it up new for $150. The fx4 will eventually replace the ehiem 2217 once its fully seeded. My question is how to position both the ehiem 2262 and fx4 intakes and returns so that I dont have sand shifting around the tank?.

 

[Jexnell]

I have two FX4s on my 125. They come with that dual outlet. I have mine with one nozzle pointed down the back wall of the aquarium, second nozzle is 45° off shooting at the front panel. Both are aimed slightly up to cause more surface agitation.

 

[FJB]

I have an FX6 in a 75gal, with the oulet (dual) as shown: Both direct water towards the glass wall first, but are angled such that the flow continues in one (the left one) towards the front, thus circling the tank along the front wall, the other (right one) towards the back,and circling the tank along the back wall. The inlet is on the other side of the tank (left side). In addition, an AC110 spills above the FX6 outlet.
In another tank, a 125g, an FX6 with an after market spray bar throws water toward thew front, slightly angled down to avoid spillings. An AC110 and Penguin 350 provide plenty of additional surface agitation.
I have not had any problems with the sand bottoms on either tank.