Re: Macerators

HeadMistress

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Re: Macerators

Graham wrote (in a thread far far away): "The Jabsco instructions dictate the location of their macerator to be on the outlet of the holding tank. Would it not be better to locate it on the outlet of the toilet so that all solids, whether they go to sea or to holding tank, are reduced to a mush?"

I appreciate that evacuating a toilet would require the macerator to run at the same time as the toilet is pumped (although the macerator might have enough suck to open the toilet non-return valve there is still the need to suck in flushing water), but would not this be kinder to the sea when pumping overboard and help the bacteriological action when the holding tank is used?

Nope...a good theory, though.

A macerator pump moves 12 gal/minute...you can't pump a toilet fast to enough to keep up with it, which would result in a lot of fried impellers in the macerator pump. Pumping a bit, then running the macerator for just a few seconds would risk a back up AND a fried impeller. If the macerator has enough pull to evacuate the bowl without pumping, it'll also pull all the rubber bits in the toilet pump out of whack.

Pureeing solid waste doesn't make it any more environmentally friendly...the bacteria count is the same...pureeing it just spreads it out over a wider area faster, which makes it LESS "friendly" to the waters around your boat. Solid waste is 75% water to begin with...going thorugh the joker valve in the toilet (assuming the joker valve is replaced often enough for the slit to remain a slit instead of a gaping hole) breaks it up enough that it dissolves very quickly in the sea or the tank--which really makes a macerator pump unnecessary for tank dumping either...and besides, unless you have a lower digestive tract problem, 90% of your flushes are only urine anyway, which doesn't need pureeing. But you'd still have the macerator in the way to deal with EVERY time you used the head.

So while it's an interesting idea--and not the first time I've heard it, either...it's just not a workable one. And you'd be just as well off--even better off--with a good quality manual diaphragm pump that can also double as an emergency bilge pump to dump your tank at sea.

(Why is this showing up as new thread instead of attaching to the "macerator" thread???)
 
Re: Macerators

[ QUOTE ]
(Why is this showing up as new thread instead of attaching to the "macerator" thread???)

[/ QUOTE ]
You've broken the forum Peggy.

You'll be banned for sure.

/forums/images/graemlins/smile.gif
 
Re: Macerators

Tough crowd! /forums/images/graemlins/smile.gif

By adding Graham's question, I think it makes a bit more sense now, anyway.
 
Re: Macerators

Thanks for all that;- erudite and thorough as usual!

I bought the macerator new at a silly price at Beaulieu but before that, had intended to do just as you suggested with a manual pump. On the up side, the macerator happened to be easier to install and hide than the manual and is it not true that some authorities require macerators?

But the bacteriological information was the most reassuring.

Thanks again Peggy.

(I was relieved to see that such an apparently attention grabbing original post had received no reads and no responses!)
 
Re: Macerators

Queensland AU is the only place I know of where only macerated waste can go overboard, but they also require that you only be at least 1 mile from the coast (most countries have a "3 mile limit"). It really makes little sense IMO...but then most marine sanitation laws don't, because they're a result of politicians caving in to the demands of overzealous environmentalists who know nothing about boats, but have convinced themselves that every flush from a boat toilet contains fecal matter.
 
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