Unless you are very, very, very disciplined in washing and drying your hydration system hose, or unless you keep it in the freezer (which gives it a bad taste), green or brown stuff will eventualy start to grow in there.

Instead of throwing away the whole thing or buying an expensive replacement hose, you can replace the hose with a cheap tube found in any hardware sotre.

Step 1: Materials Needed

You'll need the following:
- your hydration system
- utility knife
- replacement hose - vinyl tubing
- optional: any replacement part for your system

The replacement part will help you buy the tubing at your local hardware store. You be able to try different inner diameters. I tried many at the store and chose the tubing that was big enough to let the piece in but not out (that was 5/16 of an inche in my case - I have the Source system available at MEC). I recommend this approach if you don't want the new hose to leak. The tubing is typically found in the plumbing departement.

If you do not have any replacement part, you can go buy the tubing after the next step.

Step 2: Remove the Old Hose

The step title says everything... some tubes will easily pop when you pull, some will require you to cut them with the knife, as shown in the picture.

Step 3: Put New Hose

Plug in the tubing. If the tube fits too tightly on the pieces, you may need to lubricate the parts. I would recommend vegetal oil (in any case, something edible and not too tasty...).

You're done!