ZnO is probably the most studied material deposited as films by aqueous solution methods. Both neutral and alkaline solutions are commonly used, and deposition is often carried out in glass vessels. We show that for depositions carried out under alkaline conditions, slow dissolution of the glass by the solution often results in formation of zinc silicates together with the ZnO. While this silicate formation is most clearly seen after long deposition times (many hours), it can be detected already within 1 h, while often ZnO depositions proceed for substantially longer. We also describe conditions where the zinc silicate deposits without formation of ZnO providing a method of depositing such films. Finally, we note that the glass of a reaction vessel also can affect deposition of CdSe, pointing to a more general role of this normally neglected parameter.