Tunze 6150. How close to sand bed?

[HippieSmell]

I think the manual says 8 cm, but it sounded like it was only in the horizontal position. What about vertically?

 

[rvitko]

This will vary with sand grain size, in my tank I found 5" in the horizontal position was the minimum with standard 2-3mm aragonite sand. The biggest issue is once per day the pump back flushes itself for about 20 seconds and if closer to the sand this will stir up the sand and it gets sucked into the pump when it rights the direction.

 

[HippieSmell]

Is it the propeller distance to the sand we're worried about, or the end of the pump where it sucks in water for cooling?

 

[rvitko]

Both, but in a vertical orientation the 8 cm, roughly 3" distance would be sufficient as the suction is not that strong from the bottom, where we would get into trouble in the horizontal orietation is the back flushing would stir the sand so there is suspended sand to be sucked in when the direction reverses to the normal direction.

 

[HippieSmell]

Gotcha. Thanks!