I finally got tired of breathing in a strong smell of hydrogen sulphide (rotten eggs) when boarding our boat after it has been left for a few weeks. Due to general wear and tear, our Jabsco toilet and piping had been replaced at the start of the season (a quicker, cleaner, and reasonably economic option compared to replacing/repairing individual components). So, starting with a "clean sheet" (!), I decided to try and fix the lingering smelly loo problem once and for all.
Having done some basic research, it seems that this problem is common to boat toilets that use a raw (river/sea) water flush and is caused by bacteria just doing their thing (anaerobic digestion) to the water left in the pipes. Further research identified a range of low to high tech solutions available. We opted for the low cost/low tech end, and after several months usage, it seems to be working out quite well for us...i.e malodorous odours have been eliminated!
The three low tech fixes we identified use the same basic principle (disinfecting the water at the point of flushing) and were all in a similar price range. Fitting instructions for the kits were also basically very similar and dead easy to apply.
Each of the kits are fitted between the toilet pump and bowl.
After turning off the toilet seacock (you don't want to sink the ship while doing this, do you!)
Cut the toilet bowl inlet pipe approx midway and remove the recommended amount of pipe to allow for the fitting (Lazilas) or Tee piece (Purytec or Leesan).
Insert the fitting/tee piece onto the pipe ends and secure with appropriate (stainless steel) jubilee clips.
Fit the refill to the Tee piece ensuring the supplied sealing washer is correctly located.
Turn the toilet seacock back on and pump/flush away, checking for leaks.
After a few pumps, blue coloured, pleasantly aromatic, disinfected water appears in the bowl....
The disinfected water also helps keep the loo fragrant and clean in normal use.
The 'orrible smells that built up in between visits have also disappeared......
Note: We finally opted for the PURYTEC kit on the basis of being able to collect it from the Brian Ward shop in Brundall and the refills are also widely available from a number of stockists.