If brown water is coming from your hot water taps only, it may be rust and sediment in your water heater acting up. Water heaters usually have a lifespan of 10 to 15 years. If your water heater falls somewhere in this range, and your hot water comes out brown often, it may be time to replace it.
Curing is any of various food preservation and flavoring processes of foods such as meat, fish and vegetables, by the addition of combinations of salt, nitrates, nitrites, or sugar, with the aim of drawing moisture out of the food by the process of osmosis. Many curing processes also involve smoking, spicing, or cooking.
Mark is right here - you need water to cure a slab properly. Curing is the industry term for what chemists would call hydration (as opposed to de-hydration with which humans are familiar) of the cement powder. Hydration allows for increasing strength (good) and, important but often overlooked, wear resistance of the slab (really good).