Buch help

As I am finding out, in the NE, it is time for mold in the buch. I had to throw out my last batch (which I thought was my fault for waiting an extra week to feed) so I dumped, cleaned the jar, made new tea and rinsed the pellicle. I fed on Monday, thought all was fine until this morning I saw more white fuzzy stuff growing. How do I stop this from happening?!