I know this may sound dumb but I recently built my first loop. For the most part it worked out great. I had no tubing so went to Home Depot and bought some clear vinyl tubing. Problem is it is stiff and easily kinked and was hard to get on the barbs. The I.D. may be slightly too narrow. My fittings are G1/4" to 3/8" barb fittings. I am having a hard time finding the right diameter tubing and a place to buy it. Can anyone provide me with a link or any direction? Thank you.