Fifth-wheel trailers are those with living quarters inside. They can be towed with a large to medium-sized truck, depending on the size of the fifth wheel. Just as the size of the trailers themselves varies, so too does the size of their holdings tanks.
There are generally three different holding tanks on a fifth-wheel trailer. The first is a fresh water tank, the second a gray water tank and the third a waste tank. Gray water is from your sinks and showers. Waste water is from a toilet. The size of each varies depending on the manufacturer of the trailer.
Sizes - Keystone
Keystone is a manufacturer of 30 different models of fifth-wheel trailers. Their 26-foot 245RKS model has a 60-gallon fresh water tank, a 38-gallon waste water tank and a 76-gallon gray water tank. These measurements are consistent across most Keystone models.
Sizes - Dutchmen
Dutchmen is another manufacturer of fifth-wheel trailers. When dealing with Dutchmen models, holding tanks on smaller trailers are slightly smaller than those on larger ones. For example, the 30-foot 276RBS has a 52-gallon fresh water tank, 42-gallon waste water tank and 42-gallon gray water tank. The 34-foot 316FKDS, on the other hand, comes equipped with a 56-gallon fresh water tank, 42-gallon waste water tank and 84-gallon gray water tank.
- Open Road image by Chris B from Fotolia.com