### Instruction: What type of toilets do RVs have?
### Response: There are three main types of toilets found in RVs, with some rarer options available. Most RVs work off a “tank” system, with sink and shower water going into the “gray” tank and toilet waste going into the “black” tank. These tanks then need to be emptied on a regular basis dependent on their capacity. Toilets that work with a tank system tend to work like residential toilets, but use less water and have a foot pedal for flushing. There are two other types of toilets found often in DIY conversion RVs or “off-grid” RVs. First, cassette toilets are essentially holding tanks for toilet waste that are then pulled out of the RV and manually emptied. The “cassette” portion of the toilet is often on wheels, and can be emptied at either a dump station or in a public toilet. Composting toilets are the final common toilet type found in RVs. Composting toilets are a “dry” toilet, where waste goes into a holding tank with a composting material and becomes compost. The compost mixture must be stirred occasionally, but composting toilets often need to be emptied less often. There are less common toilets in RVs, for example incineration toilets, but they are not currently prevalent.