I, like many fish keepers, consistently wash my filters in tap water. I have argued this is safe multiple times and been downvoted most times. For some reason on this subreddit it has become standard belief that washing your filters in tap water will crash a cycle. Here is a graph from a study on the effect of chlorine on nitrates. On the X axis you will see the consentration of chlorine present. The Y axis has the numner of minutes needed to kill all the bacteria. Since it takes far less than 20min (maybe 1 min max) to rinse a filter it's easy to summarize that you are always fine no matter the chlorine concentrations.