Diy durso drain pipe

[sergifed91]

I built a durso pipe for the drain to sump. But not quite sure where to drill holes in it to break the siphoned. The blue dots are where I'm thinking.

 

[Peace River]

Are you planning on putting a cap on the up-tube? If not, then it doesn't seem like you would be able to get a full-siphon and there wouldn't be a need for a siphon break. If you do plan to use a cap then the top of the cap would probably be my first choice.