Overboard holding tank discharge

[Vino the Dog]

Greetings,
I am planning some far offshore distance runs and want to set up for overboard discharge of my holding tank. It does not have a through hull discharge, so must use a macerator pump attached to deck outlet. It appears most macerator pumps have a 5' self prime lift limitation and my tank to deck outlet is a bit higher than that.

Can anyone recommend a pump that's relatively inexpensive with a slightly higher lift capacity or suggest a system that will work?

thanks

[donradcliffe]

Standard system is a thru-hull with a Y-valve. Turned one way, the valve lets the toilet pump into the tank. Turned the other way, the toilet pumps overboard through the thru-hull. I can't believe that a CT-41 does not have a thru hull for each head.

[HopCar]

If you don't want to install a thru-hull I think your best bet is a manual diaphragm pump like an Edson 18. Don't forget that as the level drops in the tank, you're going to be lifting from the bottom of the tank. You're also have to store the pump and hose which will be hard to clean.

I think it's a bad idea.

I would install a thru-hull fitting lower down so you don't have to lift it all the way to the deck. If you don't want to haul the boat and install it below the waterline, install it above the waterline.

Raritan makes a new macerator pump with a shutoff valve on the intake. This makes it easier to service.

Buy a copy of Peggie Hall's book. It will have instructions on how to do the installation.

https://www.amazon.com/New-Get-Rid-B...ds=Peggie+hall

[Mr B]

This is a macerator toilet with a tank and thru hull,
The previous owner used it for 8 years and never used the tank, He was on a swing mooring a bit off shore, So it was over the side,
It has a two way valve, One is for the tank and the other is straight out thru the hull,
Install a thru hull, or you could put a thru hull just above the water line,
It would need a bit of pipe to extend it past the hull, or you will have a brown sludge down the side of your boat,

[HopCar]

Mr B brings up an interesting point about above the waterline discharge, stuff runs down the hull and leaves a streak.

One trick to avoid this is to use a thru-hull designed to be flush mounted but surface mount it instead. Take a look here GROCO MARINE PRODUCTS
It's the FTH fittings I'm talking about. Groco calls it drip control installation.

[rwidman]

Originally Posted by donradcliffe

Standard system is a thru-hull with a Y-valve. Turned one way, the valve lets the toilet pump into the tank. Turned the other way, the toilet pumps overboard through the thru-hull. I can't believe that a CT-41 does not have a thru hull for each head.

The other "standard" system has a Y valve to direct the outflow from the holding tank. The head empties directly into the holding tank (at all times) and the Y valve selects either pumping out overboard with the boat's macerator or being pumped out through a deck fitting at a pumpout station.

[rwidman]

Originally Posted by Vino the Dog

Greetings,
I am planning some far offshore distance runs and want to set up for overboard discharge of my holding tank. It does not have a through hull discharge, so must use a macerator pump attached to deck outlet. It appears most macerator pumps have a 5' self prime lift limitation and my tank to deck outlet is a bit higher than that.

Can anyone recommend a pump that's relatively inexpensive with a slightly higher lift capacity or suggest a system that will work?

thanks

Is there a reason you can't install a macerator and thru hull? It doesn't really have to be below the waterline although on a sailboat it would have to be pretty high and staining might bother you. It works fine above the waterline on my trawler because it's only a few inches above the waterline.

[Vino the Dog]

Originally Posted by donradcliffe

Standard system is a thru-hull with a Y-valve. Turned one way, the valve lets the toilet pump into the tank. Turned the other way, the toilet pumps overboard through the thru-hull. I can't believe that a CT-41 does not have a thru hull for each head.

I understand the standard system and there is a thru-hull, but the Y-valve switches between my LectraSan which direct discharges and the holding tank, which does not because the Lectra-San does. Therefore, I want a way to discharge the holding tank when there is no pump out station nearby.

Does that make sense to you?

Is there a reason so many people on this forum always assume the OP had no idea what they are doing and ignore the direct question?

[ramblinrod]

Originally Posted by Vino the Dog

I understand the standard system and there is a thru-hull, but the Y-valve switches between my LectraSan which direct discharges and the holding tank, which does not because the Lectra-San does. Therefore, I want a way to discharge the holding tank when there is no pump out station nearby.

Does that make sense to you?

Is there a reason so many people on this forum always assume the OP had no idea what they are doing and ignore the direct question?

If you don't provide essential information in your query, don't be surprised if you get irrelevant answers.

How can anyone know what your system is, or your level of understanding of sanitation systems, if you don't include that up front?

My initial response was going to be, "Do you know the difference between "suction head" and "pump head"?

Pumps blow much better than they suck.

I have no way of knowing if you know this.

Perhaps you would be better off hiring a marine sanitation consultant than using a forum and insulting the responders trying to assist with the miniscule information you have supplied?

[peghall]

I understand the standard system and there is a thru-hull, but the Y-valve switches between my LectraSan which direct discharges and the holding tank, which does not because the Lectra-San does. Therefore, I want a way to discharge the holding tank when there is no pump out station nearby.

The simplest solution would be to install Raritan's "Hold 'n' Treat" controls--a system that allows a tank to be emptied (note I did NOT say "dumped") through the Lectra/San. holdntreat controls You'd only need to add a macerator pump and some hose in addition to control system.

[pitlaw]

I have an Electro Scan. When not going direct overboard (with a Y valve close to the toilet) stuff goes direct to the electro scan. From there I can switch another Y to overboard or tank. Why? Thats the PO's plumbing. BUT from the tank the discharge to the deck pump out has another Y valve just before the deck fitting. It diverts to a standard macerator pump for overboard discharge through a different thru hull. The macerater pump is probably 3' higher and 5' away from the low tank outlet. So, maybe install a Y valve before the deck pump out and run a second hose to your macerator then out via a thru hull

Not sure if this answers your original question but its based on what I can surmise from your described problem. Plumbing is almost like electrical circuitry- you need a diagram. Good luck.

[fstbttms]

Originally Posted by Vino the Dog

Greetings,
I am planning some far offshore distance runs and want to set up for overboard discharge of my holding tank. It does not have a through hull discharge, so must use a macerator pump attached to deck outlet.

How do you plan to get the waste out of the deck fitting? Surely you don't intend to simply let it run out the top. Realize also that by pumping from below, you will be unable to empty the waste line to the deck. This all sounds like a messy, smelly disaster waiting to happen.

[EveningTide]

My boat uses a hand-powered diaphram pump to empty the holding tank. It empties thru a thru-hull below the waterline. This has worked very well for 15 years.

[a64pilot]

I just went through this, what I did was to replace the holding tank that was way overdue and when I had it made, I speced two 1.5" fittings, one connected to the hull pump out, the other to a macerator I installed, I put in a regular 1" thru hull and I don't think staining will be an issue because I only plan on pumping out when underway, and I think wave action will clean it off.
However my plan before I decided to replace the tank was to thread in a quick disconnect at the hull pump out fitting, like they use down in the keys and connect a diaphragm pump to it, the pump would only need about a foot of hose or pipe to ensure it cleared the boat completely. You would need a way to power the pump of course, but that is easy.
Clean out is just let it pump some salt water from your bucket.
However as my aluminum tank was about to go, I went the other way

[jamhass]

Similar to EveningTide, we use a simple whale diaphragm pump to empty our holding tank from the deck discharge. Pump cunnects to the fitting with nylon pipe fittings and a hose. Also a hose drapes overboard. Pump is mounter on a board. Takes about 150 pumps to clear the tank. Easy. Reliable and needs no chages to the boat plumbing.