Silence the squeaks IKEA Bed Slats [ fix for almost free]

I found some other annoying and costly solutions using felt pads and other gasket-like fixes but that didn’t make sense to me. I’ve had the bed for 3 years and before now it never squeaked. The first step to solving the problem is to identify the problem, which is the fabric they use to attach the slats gets stretched and loose. The solution from there was just to tighten it. Small problem = easy fix.
Sorry for the low-quality camera work

[Herzontix]

What is the spacing (inches) of the gap between the slats