One thing to note is that the stock fittings are for 11/8 tubing, and the "water cooling" branded tubing that's commonly-available in that size is poor quality PVC. If you hit up industrial supply companies in your respective countries, you should be able to find EPDM rubber tubing in that size that should work out much better (in terms of long-term durability and tube flexibility) though.
In the US, McMaster-Carr offers
some, and then you can find a Tygon-branded variation
elsewhere. I have some of the former coming in tomorrow, but it'll probably be about a week before I can get it swapped in and compare it to the stock tubing.