I am looking for advise on the pros and cons of locating the waste
holding tank at an elevation slightly above the toilet (aproximately
16") verses the same or lower elevation. A higher elevation would
enable gravity flow to empty the holding tank in legal waters but I am
concerned about any problems it may create in toilet function or other
unforeseen issues. I would rather ask than create a stink!

Bruce Richards wrote:
I am looking for advise on the pros and cons of locating the waste
holding tank at an elevation slightly above the toilet (aproximately
16") verses the same or lower elevation. A higher elevation would
enable gravity flow to empty the holding tank in legal waters but I am
concerned about any problems it may create in toilet function or other
unforeseen issues. I would rather ask than create a stink!

I wouldn't call 16" a "slight" elevation above the toilet...that puts
the bottom of the tank above the top of the bowl. I wouldn't do
it...'cuz that's likely to leave waste and/or flush water in the head
discharge hose to run back down into the bowl...how much depends on how
long the head discharge hose is.

I suggest you find a location within 6' of the toilet that will put the
tank close the same level as the toilet. It's ok if the bottom of the
tank is a few inches above the base of the toilet, 'cuz you should have
a loop in the head head discharge line immediately after the toilet
that's above the top of the tank anyway--to prevent heeling from sending
waste in the tank back into the bowl.

You're not limited to the few rectangular tanks shown in the marine
catalogs, btw...Ronco Plastics makes even better quality tanks for a
very reasonable price, and have more than 400 shapes and sizes to choose
from--including over 100 that are non-rectangular to fit just about any
space on a boat. And they install fittings in the sizes and locations
specified by the customer when they make the tank. Their catalog is on
their website at http://www.ronco-plastics.com (I don't have any
connection with 'em, btw...they supplied at least 90% of the tanks we
sold when I still owned my company.)

If you'd like some help in spec'ing out a system you'll be happy with
(or as happy as it's possible to be with a holding tank--at least
trouble-free and odor-free, anyway), I'll be glad to help you.
--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/detai...=400&group=327

http://www.seaworthy.com/html/get_ri...oat_odors.html

On 5 Dec 2003 15:35:39 -0800, (Bruce Richards)
wrote:

I am looking for advise on the pros and cons of locating the waste
holding tank at an elevation slightly above the toilet (aproximately
16") verses the same or lower elevation. A higher elevation would
enable gravity flow to empty the holding tank in legal waters


but I am
concerned about any problems it may create in toilet function or other
unforeseen issues. I would rather ask than create a stink!

And well you should be.

I am looking for advise on the pros and cons of locating the waste
holding tank at an elevation slightly above the toilet (aproximately
16") verses the same or lower elevation.

I made my holding tank out of that blue pvc 10" sewer pipe & mounted it so the
bottom was just above the waterline.

On Fri, 05 Dec 2003 15:35:39 +0000, Bruce Richards wrote:

I am looking for advise on the pros and cons of locating the waste holding tank
at an elevation slightly above the toilet (aproximately 16") verses the same or
lower elevation. A higher elevation would enable gravity flow to empty the
holding tank in legal waters but I am concerned about any problems it may create
in toilet function or other unforeseen issues. I would rather ask than create a
stink!

I'm not sure there's any great advantage to "gravity flow to empty the tank" -
there's much to be said for a macerating pump!

Also, there are many advantages to having both inlet and outlets on the TOP of
the tank (with a pipe going down to the bottom for the outlet), including little
or no sewage sitting in the hoses and stinking. With this setup, you would still
need a pump to empty it.

There's also the consideration that, if the tank is any decent size, it's pretty
heavy when full - better have that weight low!

Lloyd Sumpter
"Far Cove" Catalina 36 - just installed 135L tank last fall.

My Head is in the forward middle and well below the deck I would say at
least below the bottom of the waste tank with a line at least 10' or 12'
long, I can see where a shorter line would be easier to pump, ( I have a
manual head ) I had it clog this yr., but I never had it back up, that is
unless I took the line apart when I unclogged it which I didn't with a full
tank. The tank bottom seems to be above the top of the toilet, the top of
the waste tank comes up to the top deck in the cockpit. I never had any
problem with it backing up though, the head has a pretty good check valve on
it I guess. PS this is a stock 1994 26' Chris Craft Crowne, w/ aft cabin.
good luck
"Lloyd Sumpter" wrote in message
...
On Fri, 05 Dec 2003 15:35:39 +0000, Bruce Richards wrote:

I am looking for advise on the pros and cons of locating the waste
holding tank
at an elevation slightly above the toilet (aproximately 16") verses the
same or
lower elevation. A higher elevation would enable gravity flow to empty
the
holding tank in legal waters but I am concerned about any problems it
may create
in toilet function or other unforeseen issues. I would rather ask than
create a
stink!

I'm not sure there's any great advantage to "gravity flow to empty the
tank" -
there's much to be said for a macerating pump!

Also, there are many advantages to having both inlet and outlets on the
TOP of
the tank (with a pipe going down to the bottom for the outlet), including
little
or no sewage sitting in the hoses and stinking. With this setup, you would
still
need a pump to empty it.

There's also the consideration that, if the tank is any decent size, it's
pretty
heavy when full - better have that weight low!

Lloyd Sumpter
"Far Cove" Catalina 36 - just installed 135L tank last fall.

Wildest Dream wrote:
My Head is in the forward middle and well below the deck I would say at
least below the bottom of the waste tank with a line at least 10' or 12'
long, I can see where a shorter line would be easier to pump, ( I have a
manual head ) I had it clog this yr....

That's about twice as far as the optimal distance from the toilet. As
for why it clogged, unless someone tried to flush something they
shouldn't have, it was most likely because you don't flush long enough
to move bowl contents all the way to the tank. That can be compounded by
a buildup of sea water minerals and urine crystals in the head discharge
hose.

When the tank is that far from the toilet, it's just about impossible to
flush long enough rinse out the hose every time the head is used without
filling up the tank with flush water. The solution: once a day--or at
least at the end of every weekend aboard, close the intake seacock (it
should always be closed while you're away from the boat anyway) and pour
a couple of quarts of clean fresh water into the bowl and flush it
through using the "dry" mode. Follow that with a cupful--no more--of
white vinegar, also flushed through in the dry mode. Do not leave
vinegar sitting in the bowl...that will destroy the joker valve in the
toilet.

...I never had any
problem with it backing up though, the head has a pretty good check valve on
it I guess.

It's called a joker valve, and it should be replaced at least every two
years if you want to keep working.

PS this is a stock 1994 26' Chris Craft Crowne, w/ aft cabin.

Most boatbuilders' "stock" sanitation system designs are the weakest
link on their boats....They totally ignore the concept that it IS a
system. So they stick the cheapest toilet in the head, use the cheapest
hose, and put a tank wherever there happens to be a space it'll fit in.
If they took the same approach with the fuel system that they do with
sanitation systems, their boats wouldn't run and 99% of would be
destroyed by fire in the first year.

Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/html/get_ri...oat_odors.html

Pvc pipe, what a unique idea. Knew a guy once that replaced his 15 ft. run of
exhaust pipe with pvc, saved a fortune.!

Florida Keyz wrote:
Pvc pipe, what a unique idea. Knew a guy once that replaced his 15 ft. run of
exhaust pipe with pvc, saved a fortune.!

And will prob'ly spend 3x as much as he saved correcting the problems it
caused...'cuz PVC isn't recommended for any pipe exposed to that much heat.

It's also a highly risky choice in sanitation systems.

Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/detai...=400&group=327

http://www.seaworthy.com/html/get_ri...oat_odors.html

"Bruce Richards" wrote in message
m...
I am looking for advise on the pros and cons of locating the waste
holding tank at an elevation slightly above the toilet


If you can locate the tank lower than the toilet, you will be MUCH happier
in the long run!

Pumping the tank overboard (in legal areas) is not a big issue. The pumps
are fairly reliable.

The toilet is not so reliable. If the tank is higher than the toilet, I
would fully expect the contents of the line to the tank to leak back into
the toilet bowl. If you do this, I certainly hope that the line from the
toilet attaches at the top of the tank so that the entire tank can't empty
back through the toilet!

Eventually you will have to work on that toilet, which may mean that you
will have to remove the hose between the toilet and the tank If it is
uphill to the tank, you will have a hose full of crap spill out into the
head.

Rod