Jar for Ramshorn/Bladder snails

Hey! Very new to aquarium stuff, please correct me if i’m wrong but heres what I know so far:

•Source of Calcium, Boiled egg shells with membrane removed

•Lid, I can use plastic wrap with a few holes

•Since there is no filter other than plants, I will have to do water changes

•(correct me if I’m wrong) I can use tap water and leave it for 24 hours to remove chlorine as water for the jar

Questions: How often should i do water changes How do i clean the poop after a while? If im using rocks as a substrate Do i need to worry about having disturbances in the water for aeration Do i need to worry about the cleanliness of tap water

Thank you in advance