Toilet Additives

[LittleSister]

I don't think the distance between the seacock and the filter is relevant as the seawater between those two is just seawater and it's not going to cause a problem.

The smell arises in the trapped seawater in the inlet side of the toilet pump from the small amount of fecal matter transfer from the outlet side of the piston to the inlet side.

That's incorrect.

It is the decay of the tiny creatures in the seawater trapped in the pipe between the seacock and the inlet pump that causes the smell, not fecal matter.

You can get the same initial smell issue with Lavac toilets, and they don't have the sort of combined inlet and outlet piston you mention in their pumps

As others have mentioned, you don't get that smell at all when the toilet is in frequent use. That's because the creatures are still living if they haven't been in the pipe for too long.

(And if you are getting any significant amount of fecal matter washing back into your toilet inlet pipe, I'd suggest changing/refurbishing your pump! )

The distance between inlet seacock and toilet is relevant, insofar as if that is short the smelly water is very quickly pumped through, whereas a long inlet pipe run might take significantly more pumping.

 

[RichardS]

That's incorrect.

It is the decay of the tiny creatures in the seawater trapped in the pipe between the seacock and the inlet pump that causes the smell, not fecal matter.

You can get the same initial smell issue with Lavac toilets, and they don't have the sort of combined inlet and outlet piston you mention in their pumps

As others have mentioned, you don't get that smell at all when the toilet is in frequent use. That's because the creatures are still living if they haven't been in the pipe for too long.

(And if you are getting any significant amount of fecal matter washing back into your toilet inlet pipe, I'd suggest changing/refurbishing your pump! )

It is correct. You can keep clear seawater as long as you like and it will never decompose to produce hydrogen sulphide.

Of course you don't get the smell when the toilet is regularly used. All bacterial decomposition takes time, whatever the source.

It only requires a small amount of fecal transfer. You can change/refurbish the pump every week but it is not going to make any difference as the transfer is inherent in the Jabsco design.

I don't know about the Lavac but if the smell is hydrogen sulphide (bad egg) there then it is almost certainly caused by fecal matter decomposition, although not necessarily in the pump.

If there is genuinely never any residual fecal matter in a Lavac, then it will not smell in most of the Med away from cities because the seawater contains so little fecal matter. The seawater around other countries/locations will be different and sometimes you might get the smell and sometimes not.

Richard

 

[pvb]

I don't think the distance between the seacock and the filter is relevant as the seawater between those two is just seawater and it's not going to cause a problem.

The smell arises in the trapped seawater in the inlet side of the toilet pump from the small amount of fecal matter transfer from the outlet side of the piston to the inlet side. What happens is that with every pump some of disinfectant is flushed through from the filter to the pump. When the toilet is being flushed regularly it's not doing much but, as soon as you leave the pump alone, that disinfectant in the water left in the inlet side of the pump kills the bugs so they cannot develop the smell. The next time you use the pump, which could be weeks or months later there is no smell as there is no fecal transfer is the pump is not being used.

The relative location of the seacock, filter and pump won't make any difference to the efficacy of the system.

Sorry, I disagree with you.

 

[RichardS]

Sorry, I disagree with you.

Fair enough ..... I am a pioneer, if not the actual inventor, of the marine urinal block system so it will take a few decades before full acceptance is achieved.

Richard

 

[pvb]

Here's an extract from a post by none other than Peggie Hall herself, on another forum...

"Stagnant sea water trapped in the head intake is a major source of TEMPORARY odor...odor that goes away as soon as the first flush flushes all the stagnant water out of the intake and pump. Teeing the intake line into the head sink drain line is an excellent solution, 'cuz it provides a means providing clean fresh water to rinse the sea water out of the WHOLE system before it can stagnate. Unfortunately just pouring fresh water into the bowl doesn't work very well...'cuz bowl contents aren't recirculated through the intake line, pump and channel in the rim of the bowl (thank goodness!)....whatever is in the bowl only goes out the bottom part of the pump and down the discharge line."

Show Posts - Peggie Hall

 

[RichardS]

Here's an extract from a post by none other than Peggie Hall herself, on another forum...

"Stagnant sea water trapped in the head intake is a major source of TEMPORARY odor...odor that goes away as soon as the first flush flushes all the stagnant water out of the intake and pump. Teeing the intake line into the head sink drain line is an excellent solution, 'cuz it provides a means providing clean fresh water to rinse the sea water out of the WHOLE system before it can stagnate. Unfortunately just pouring fresh water into the bowl doesn't work very well...'cuz bowl contents aren't recirculated through the intake line, pump and channel in the rim of the bowl (thank goodness!)....whatever is in the bowl only goes out the bottom part of the pump and down the discharge line."

Show Posts - Peggie Hall

Unfortunately Peggie is not correct, I'm afraid.

Salt has reasonably good anti-bacteriological properties and in clean seawater, it is strong enough to kill most bacteria in a closed sample. Clear seawater is generally free of bacteria and is mildly anti-bacterial unless it has been contaminated. However, it is certainly not strong enough to overcome the massive bacterial load caused by human fecal contamination.

If you installed a new Jabsco and never actually used it for its intended purpose in a clear sea the smell would never arise.

Richard

 

[pvb]

Unfortunately Peggie is not correct, I'm afraid.

Hmm...