Can anyone tell me how to keep the poly in furrow fertilizer line from rubbing the disc openers?

I currently have been using the totally tubular in-furrow fertilizer tubes with the seed tube guards. They have wore out(seed tube guard part) and I was sent this seed tube guard with fertilizer tube to mockup on my planter to see if I like it. When I asked the company (who I am not going to mention) how to secure the poly fertilizer tube, they told me to duck tape it. I could not believe this answer. Has anyone ever used this type of fertilizer/seed tube guard setup for in-furrow fertilizer application and how did you secure the fertilizer line? The seed tube guard is supposed to last up to 5 times longer than standard or OEM brands. That's why I thought I would give it a try. Maybe I should just stay with the totally tubular brand. Thanks for you ideas and opinions.