I’m going to parrot Webster1234 here on this.
He told me once to qt everything. He even had a qt for snails and cuc going on one visit. I thought it was excessive at that time but I was wrong. Anytime you had any cuc/fish to your system that isn’t properly qt,’d you’re running a risk of introducing something you do not want. I’m convinced an order from reef cleaners introduced something causing me to lose my blue line that had been with me for 2.5yrs and my fowleri for 3 yrs. I was crushed
caveat emptor