Bought some Fiji pink from someone that broke their tankdown. It needs to be rinced as it was sitting in buckets for a few weeks. Can I rinse with tap water or do I have to use RO?
What I do is get a big rubbermaid and put the sand in that in the tub. Use tap and just swish it around then use something to scoop out the dirty water. Just keep doing that until it is clean and then I use RODI for final rinse.
Depends on what you want to accomplish by rinsing. If you consider this as live sand, you would not expose it to fresh water. By analogy, who rinses live rock with freshwater? Fresh water will kill things in the sand. Will it kill beneficial bacteria? I don't know. Do you want to do the experiment?
Will exposure to freshwater improve the sand? I saw results from a study of phosphate absortion by aragonite. Phosphate tends to be released at pH's above and below that which we maintain in aquarium. So, if the used sand has absorbed phosphate, they might be released, but when? During the rinse or when it is placed in the aquarium?