How long should the supply line be bettween the wall and the toilet?

[Spbphil]

How long should the water line connector be to the toilet? At present I have installed one that is just about 2" longer than the distance, so there is a twist in it.
My local plumbing supply place said to get a significantly longer one, and loop it around in a circle, then attach to the toilet. The argument is that it puts less pressure on the plastic connectors.
Why does it matter? A couple of years ago I was sitting in my livingroom and heard a loud noise coming from the hall bathroom--the plastic connector had cracked off and I heard a loud and unusual sound--and there was water everywhere. I turned off the water at the wall, and put in a replacement line. TG this did not happen while I was out of town!
But now I am wondering if I should install the much larger one to prevent a future catastophe.

 

[Jadnashua]

You want it long enough so that there's no stress on the line. Long enough for a loop works, but it doesn't have to be that long depending on the orientation.

 

[Sponsor]

 

[Spbphil]

Here are photos of the connectors for two toilets, showing the twist in each one. That's what I'm concerned about, since that puts pressure on the plastic connector--like the one that broke a few years ago.
Since I'm replacing the flow valve on one, so a good time to make any changes. Here are the two supply lines with twists.
Replace? Keep? Goal: Peace of mind.

 

[Terry]

The length looks fine. The supply with the gray nut is a stronger nut than the white one. I would replace the supply with the white nut.