Size Matters

[PaulJ]

I am planning the installation of a holding tank. Of course space is limited but I have no idea how much capacity is needed for such a tank. Could anyone out there please tell me the capacity of your tank and how often does it have to be emptied with say two people using it.

 

[billmacfarlane]

My boat is 11m long and the holding tank has a capacity of 45l.

 

[hlb]

Mine has 10 gallon if I remember correctly. If your on the sea you could manage on less.

No one can force me to come here-----------
----- I'm a Volunteer!!!

Haydn

 

[Peter_the_Grate]

How about coming at it from the other direction, so to speak? What goes in must come out, i.e. into you and out of you - 2.5 litres of water/fluids per day per person on average, plus the grub ... er ... compacted a bit.

 

[hlb]

Ah but. Depends how much water is used to flush it all down.

No one can force me to come here-----------
----- I'm a Volunteer!!!

Haydn

 

[Peter_the_Grate]

... that's the easy bit.

((-)

 

[PaulJ]

Thanks for your replies, any advances on 10galls/45ltrs..?

 

[pvb]

A different plumbing option...

I know you had some other replies on CWBB, and that you've looked at Gerry's website. I reckon there's a better plumbing option for the type of installation where the holding tank is above the toilet. First think of a regular toilet, with the outlet connected to the seacock. Now imagine the outlet hose goes to a T-piece; one side of the T goes to the seacock, the other goes upwards to the bottom of the holding tank. If you want to use the holding tank, just close the outlet seacock and toilet pumping action forces waste up into the holding tank. (Note that this will only work if the toilet has a joker valve on the outlet - most do, but I don't think the Lavac does). To empty the tank, just open the seacock. Best advantage of this option is that every time you pump into the holding tank, you stir up the contents, thus overcoming the biggest potential problem with Gerry's version (that of waste blocking the outlet).

If you add another valve at the bottom outlet of the holding tank, you can choose to use the holding tank for solids, whilst also having the option of pumping straight out for liquids. (Was that delicate enough?)

Finally, if you're going to use the holding tank seriously, just buy the biggest one which will fit the available space.

 

[PaulJ]

Re: A different plumbing option...

Many thanks pvb what you say makes a lot of sense. My only reservation would be whether the Tee piece would be a potential place for a blockage..... have you used this system yourself?