Holding Tank Installation

While inspecting our current boat before we bought her, we noted that she was not equipped with a holding tank.  Because some of her previous adventures were extended sailing across the Pacific, it made sense that this would work.  We, starting out as coastal sailors, would need one.

After some planning on how the holding tank should be plumed I opted for a simpler design where the toilet would dump into the tank, and then the tank could be pumped out into the ocean once we were the required distance from shore.  I also wanted to install a macerator to aid in the pump out.

Although I wanted the largest tank possible, I also wanted to keep as much storage space on the boat as possible.  After looking into all the nooks and crannies where the tank could go, I decided to mount her under the sink in the head.  This was a space that could not be used and it would also contain any possible smells in one area – namely the head.  I found that a six-gallon tank wedge tightly into the space I chose.

As it turned out the Jabsco macerator could either have a hose running from the tank to it, or screw directly into the tank.  To keep the number of fittings to a minimum, screwing the macerator directly into the tank seemed like the logical choice.  My other issues were that I needed to adapt the existing 1 3/4” hose from the toilet to the 1 1/2” hose going into the tank, and then adapt back to the 1 3/4” hose to exit the boat.  That was not too difficult.


In testing the installation with clean water, I noted that the plug in the lower corner tank that would have been used as a vent if I had mounted the tank another way, was leaking.  I drained the tank, put good glue around the plug and reinstalled it.  After that all seemed to work well.  Not a big deal, but it was something that no one seemed to address in any of the postings that I have read.

All I have left is to run some decent wire from the fuse box to the macerator and wire a button to activate it.  In testing the macerator I did notice that it seems to make a noise that I will keep an eye on.  A kind of rumbling noise.