P
PGK
Guest
It's a parasite so yes it can come back at anytime. Your other filter media will hold plenty of bacteria. Now, there are meds that will kill your bacteria. I've had great success using 80-82F temps and a tablespoon of aquarium or kosher salt per gallon for about a week and then slowly dropping the temp back to normal and doing partial water changes to remove the salt. No need to remove you charcoal at all.