[Histonet] DAB precipitate on H. pylori

[Dorothy Glass]

I have been getting something on some slides, not all that looks like bacteria but it is not. It looks like Dab precipitate. It looks like the Dab is breaking down,  but only noticeable on the stains for H. pylori.  I wash my water bath, and changes my blades. It not occurs all the time, but it has happened about four times.  Could it be the water not being filtered properly. We have a water filtering system, but it has not been working well lately. Would that have anything to do with the brown patches on H. pylori?