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How to Unclog a Marine Head Toilet

by Sarah Silverman

A marine head toilet is a specially designed waste management system for use on boats and yachts. The toilet uses the minimum amount of water needed by drawing up surrounding seawater through a system of valves and pumps. Occasionally your marine head become clogged due to scale and other buildup. You can easily deal with the clog by introducing a very corrosive and strong acid into the toilet to clear the blockage without any special tools.

Step 1

Put on gloves and a respiratory mask. The acid you will be handling is very harsh, so you shouldn't breathe it in or get any on your skin. Ventilate the area as well as you can.

Step 2

Measure out 2 cups of 10 percent muriatic acid solution into a acid-safe container, like plastic. Do not use metal, as it will react with the solution.

Step 3

Pour the acid directly into the bowl of the head and allow it to fizzle in with the water.

Step 4

Leave the acid in the head until the water stops fizzing completely. Pump or flush the head until the water just leaves the head.

Wait 5 minutes to allow the acid to work through the lines, and fully discharge the head.


  • Avoid clogs by pouring vinegar down the head once a month for 5 minutes each time.


  • Seek medical attention immediately if the acid gets into your mouth, eyes or other orifice.

Items you will need

  • Gloves
  • Respiratory mask
  • 10 percent muriatic acid solution
  • Acid-safe container

About the Author

Based in West Windsor, N.J., Sarah Silverman has been writing computer- and electronics-related articles since 1990. Her articles have appeared in “Wired” and “Ericsson” magazines. She received the Kim Swiss Award in 2006. Silverman holds a Bachelor of Arts in journalism from the University of Rochester in New York.

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