When using flavors, keep those trays apart from others, when the taste is strong enough to transfer to the next batch. Use non-metal molds when freezing liquids that have a high acid content. If your water is high in mineral deposits, a film can form on your ice molds, as it does on your drinking glasses. This also happens from plain soap film. To remove it, just soak in a vinegar and water solution for about 20 minutes, then rinse thoroughly.
When using flavors, keep those trays apart from others, when the taste is strong enough to transfer to the next batch. Use non-metal molds when freezing liquids that have a high acid content. If your water is high in mineral deposits, a film can form on your ice molds, as it does on your drinking glasses. This also happens from plain soap film. To remove it, just soak in a vinegar and water solution for about 20 minutes, then rinse thoroughly.