Most manufacturers suggest that hoses be replaced every 4-6 years. If you aren’t sure how old your hoses are, a lot of hoses are stamped with a date. We check each hose that arrives in our facility and suggest when hoses should be replaced. We won’t make any replacements unless the customer approves them.
If the hose is old but does not show signs of a failure, we will tag the hose, but leave it installed. If the hose does show signs of failure, such as a hole, we will remove it from the system, place it in a red bag, and suggest a replacement.
It is very important to take these recommendations seriously as a failed hose is hard to account for underwater and would often lead to a shared-air ascent with a buddy.