How large is the conduit that contains the fiber optic cable? The conduit ranges in size from ¾ inch to 2 inch, but our standard is ¾ inch. Not the solution you were looking for?Click the link below to submit a support ticketSubmit Ticket Updated on July 2, 2019 Was this article helpful? Yes No Related Articles My Fiber Line Has Been Buried. Now What? How do I contact ALLO about a construction related issue, question, or concern? Who takes care of the damage subcontractors do to my property? Are there city mandated hours in which construction can be performed? What variety of grass seed will ALLO use to replant in the spring? How will I be contacted regarding the start of construction?