Siphon Break in Loc Line?

[GreenSpottedPuffer]

My return is PVC straight up the back of the tank where there is one 90 elbow to get parallel to the top of the tank and then from there the rest is Loc Line.

My problem is, where to I drill a siphon break? Right in the Loc Line? I really don't want to but it seems that is the only place. The 90 elbow is sitting ontop of the trim, so can't be drilled or the water trickling out will just go down the back of the tank.

Or do you think I should just keep the Loc Line right at the water surface so back siphoning is not a real issue? I guess it would give great surface agitation. The return pump is quite small and I am not relying on it for flow at all but the extra flow behind the rocks was going to be nice.

What do you think?