Function

• There are three types of holding tanks in recreational vehicles (RVs). When you camp without utility hookups, your fresh water tank stores cooking, bathing and toilet flushing water. Whether connected to utilities or not, gray water tanks capture the waste water from cooking and bathing. The black water tank holds toilet waste. Exterior vent fans can eliminate odors as well as tank chemicals that have varying degrees of effectiveness. Proper tank treatments can eliminate odors and prevent costly repairs because of clogged release valves.
  
  

Prevention/Solution

• Fresh water tank care begins with a water filter connected to your RV's intake hose. These filters trap impurities, resulting in better-tasting water and a clean tank.
  
  Gray-water tanks are also easily maintained. Use a trap in all sinks and tubs to collect solids. A gray-water tank valve can stay open while connected to utilities, but occasionally closing it, filling the tank with waste water and draining it will help remove trapped debris. For additional cleaning power, add two cups of water softener and one gallon of hot water beforehand.
  
  Black-water tank treatments begin by using one-ply toilet paper that breaks down easily. Keep the valve closed when connected to utilities, and never empty your tank until it's at least halfway full.
  
  

Expert Insight

• You can eliminate unpleasant fresh-water taste or possible tank contamination by sanitizing with a bleach and water solution. A recipe found at Camping.com explains:
  
  "Drain your tank, fill half way with fresh water, add ¼ cup of bleach for every 15 gallons your tank holds, fill tank, run cold water through your faucets, run the hot water to get the bleach water solution in your hot water tank. Let stand for four to six hours. Drain the tank (including hot water tank via faucets) completely. Mix ½ cup of baking soda with a gallon of water, pour into tank and refill tank. Open all faucets to allow the fresh water to pump throughout the system--this step removes the bleach odor. Drain tank once again and refill--ready to use" (see Reference 1).
  
  

Considerations

• RV holding tanks are not a septic system. Unlike a septic system, holding tanks do not break down waste, even when treatments are used. Never put cooking grease, sanitary products or harsh cleansers down the drain.
  
  

Warning

• RV supply stores sell tank treatment chemicals, but preventative maintenance is best for the planet. If you purchase tank treatments, always buy environmentally friendly products without formaldehyde. Harsh chemicals kill beneficial bacteria in septic systems, causing damage and eventually resulting in costlier park fees for all RVers.