PETG Pipe Shrinkage

Hello Everyone,

About a week ago I ran into an interesting problem. After noticing my loop was leaking I drained it and pulled it apart. The PETG pipe ends that were inserted into the fittings had all shrunk and were the core issue with the leaks. I’ve since replaced all the pipes but noticed that almost all my fittings were unusually loose a little bit ago and am afraid it is happening again. I’m not sure if I’m doing something wrong on my end or if I should just switch to acrylic tubing (assuming it’s more substantial than PETG). Any thoughts?

For industrial use they only use petg for cool liquids

I’m thinking of something else nevermind