Holding Tank vs Portable MSD

[Steve Groh]

I just purchased a 1974 Eriksen 25 with a Jabsco toilet with raw water inlet and discharge – no holding tank.
Most of my use will be inland; however, there is a good chance that she will end up in salt water.
Should I plumb the existing head to a new holding tank or consider a portable option plumbed to either pump out or discharge in blue water?

 

[Tally Ho]

Personal choice really. Some things to consider…

On a 25-foot boat, it might be hard to find room for a holding tank. Also way more complicated than using a portapotty.

Is there a pumpout facility on the lake you plan to sail? If not, then a portapotty makes sense.

That said, I have a holding tank on my boat, and prefer pumping it out at the fuel dock more than I would relish carrying the portapotty tank to the marina bathroom and dumping it…

My son is in Boulder…beautiful country !


Greg

 

[Steve Groh]

Personal choice really. Some things to consider…

On a 25-foot boat, it might be hard to find room for a holding tank. Also way more complicated than using a portapotty.

Is there a pumpout facility on the lake you plan to sail? If not, then a portapotty makes sense.

That said, I have a holding tank on my boat, and prefer pumping it out at the fuel dock more than I would relish carrying the portapotty tank to the marina bathroom and dumping it…

My son is in Boulder…beautiful country !


Greg

The E25 has plenty of room under the V berths for as large a tank as I would ever want, and I have a berth at Dillon Marina, which has excellent services, including a pump-out station.

 

[Peggie Hall HeadMistress]

On any boat much smaller than about 30' a self-contained system—an "MSD" portapotty--makes a lot of sense. The "MSD" designation in the model name/number means it has fittings for a pumpout line and vent line, and is designed to be permanently installed (actually just sturdier brackets than portables, so you could still take it off the boat if you absolutely have to), which means that although it's still called a PORTApotty, you don't have to carry anything off the boat to empty it.

A 5-6 gallon model is household height and holds 50-60 flushes...you'd need at least a 30 gal tank to hold that many from a manual marine toilet. No plumbing needed except a vent line and pumpout hose--so no new holes in the boat...and -0- maintenance needed except for rinsing out the tank--which you can do with a bucket while it's being pumped out. Total cost including the pumpout hose and vent line is about $300--a fraction of what you'd spend for toilet, tank and all the related plumbing needed. And the best part is, you have all the advantages of a toilet and holding tank without giving up a single square foot of storage space.

If this idea appeals to you, check out the Dometic/SeaLand 975MSD

--Peggie

 

[Steve Groh]

On any boat much smaller than about 30' a self-contained system—an "MSD" portapotty--makes a lot of sense. The "MSD" designation in the model name/number means it has fittings for a pumpout line and vent line, and is designed to be permanently installed (actually just sturdier brackets than portables, so you could still take it off the boat if you absolutely have to), which means that although it's still called a PORTApotty, you don't have to carry anything off the boat to empty it.

A 5-6 gallon model is household height and holds 50-60 flushes...you'd need at least a 30 gal tank to hold that many from a manual marine toilet. No plumbing needed except a vent line and pumpout hose--so no new holes in the boat...and -0- maintenance needed except for rinsing out the tank--which you can do with a bucket while it's being pumped out. Total cost including the pumpout hose and vent line is about $300--a fraction of what you'd spend for toilet, tank and all the related plumbing needed. And the best part is, you have all the advantages of a toilet and holding tank without giving up a single square foot of storage space.

If this idea appeals to you, check out the Dometic/SeaLand 975MSD

--Peggie

Thank you so much for the reply, Peggy. That is excellent advice! Does your book cover plumbing for such an installation?

 

[Peggie Hall HeadMistress]

There's not enough to installing to require much if any instruction beyond what comes with the potty. And --and anyone else who's installed one--can walk you through anything that isn't clear.

Defender's listing for it includes the instructions Dometic SaniPottie 975MSD Toilet with MSD Fittings - Gray | Defender Marine and they have it on sale.

--Peggie

 

[Steve Groh]

There's not enough to installing to require much if any instruction beyond what comes with the potty. And --and anyone else who's installed one--can walk you through anything that isn't clear.

Defender's listing for it includes the instructions Dometic SaniPottie 975MSD Toilet with MSD Fittings - Gray | Defender Marine and they have it on sale.

--Peggie

That's the one I was looking at.
On its way!
Thanks!

 

[Alan Gomes]

There's not enough to installing to require much if any instruction beyond what comes with the potty. And --and anyone else who's installed one--can walk you through anything that isn't clear.

Defender's listing for it includes the instructions Dometic SaniPottie 975MSD Toilet with MSD Fittings - Gray | Defender Marine and they have it on sale.

--Peggie

Hi, Peggy.

Can you comment on how robust the mounting brackets are on the 975MSD? I'm just curious. I have a Thetford 550P and the flimsy plastic mounting hardware is something of a joke. I went with a custom fabricated stainless bracket that holds it solidly so I don't have to worry about the head coming loose in a seaway. It looks like the 975 mounting hardware might be a bit more substantial. I'm just wondering because I know the 550P is no longer in production, and if I ever needed to replace it in several years I'm wondering how the 975 might compare.

Thanks.

 

[rgranger]

On any boat much smaller than about 30' a self-contained system—an "MSD" portapotty--makes a lot of sense. The "MSD" designation in the model name/number means it has fittings for a pumpout line and vent line, and is designed to be permanently installed (actually just sturdier brackets than portables, so you could still take it off the boat if you absolutely have to), which means that although it's still called a PORTApotty, you don't have to carry anything off the boat to empty it.

A 5-6 gallon model is household height and holds 50-60 flushes...you'd need at least a 30 gal tank to hold that many from a manual marine toilet. No plumbing needed except a vent line and pumpout hose--so no new holes in the boat...and -0- maintenance needed except for rinsing out the tank--which you can do with a bucket while it's being pumped out. Total cost including the pumpout hose and vent line is about $300--a fraction of what you'd spend for toilet, tank and all the related plumbing needed. And the best part is, you have all the advantages of a toilet and holding tank without giving up a single square foot of storage space.

If this idea appeals to you, check out the Dometic/SeaLand 975MSD

--Peggie

I had one of these types on my last sailboat. Easy peasy

 

[Peggie Hall HeadMistress]

Can you comment on how robust the mounting brackets are on the 975MSD?

They're a good bit sturdier than the ones for the portable units, but I can't fault you if you want to install some that are even sturdier. Just make sure they aren't so sturdy that you can't open 'em to take the tank out to dump it if/when you ever have to.

--Peggie

 

[Erbardy]

On any boat much smaller than about 30' a self-contained system—an "MSD" portapotty--makes a lot of sense. The "MSD" designation in the model name/number means it has fittings for a pumpout line and vent line, and is designed to be permanently installed (actually just sturdier brackets than portables, so you could still take it off the boat if you absolutely have to), which means that although it's still called a PORTApotty, you don't have to carry anything off the boat to empty it.

A 5-6 gallon model is household height and holds 50-60 flushes...you'd need at least a 30 gal tank to hold that many from a manual marine toilet. No plumbing needed except a vent line and pumpout hose--so no new holes in the boat...and -0- maintenance needed except for rinsing out the tank--which you can do with a bucket while it's being pumped out. Total cost including the pumpout hose and vent line is about $300--a fraction of what you'd spend for toilet, tank and all the related plumbing needed. And the best part is, you have all the advantages of a toilet and holding tank without giving up a single square foot of storage space.

If this idea appeals to you, check out the Dometic/SeaLand 975MSD

--Peggie

Hi,
I just purchases a 1986 catalina 30 that has the original sanitation system in it and it has a smell. I went back and forth on what to do and just concluded doing a MSD set up with that same porta potty you mentioned (dometic) which i already have from my previous boat. I am going to drill a new deck waste fitting through directly above the toilet so that there is less sanitation line since the stock waste deck fitting is located 17 feet aft of the head. Any advise?

 

[Peggie Hall HeadMistress]

What size is your MSD potty?
Don't try to save money by going with cheap hose... Raritan SaniFlex is the top rated hose..warranted against odor permeation for 10 years; Defender has it for about $10/ft and sells it by the foot.
Raritan Sani / Flex Sanitation Hose at Defender

You'll also need to install a vent thru-hull a lot closer to the toilet. I wouldn't put it directly above the toilet, though...I'd find a location about a foot below toe rail that'll let you run a vent line a bit longer than it would be going straight up to keep the vertical rise below 45 degrees. And, I'd enlarge the vent fitting on the tank to use a 1" line and use a 1" open "bulkhead" thru-hull. That'll provide a lot more air exchange, which is the key to preventing odor out the vent.

--Peggie

 

[Erbardy]

What size is your MSD potty?
Don't try to save money by going with cheap hose... Raritan SaniFlex is the top rated hose..warranted against odor permeation for 10 years; Defender has it for about $10/ft and sells it by the foot.
Raritan Sani / Flex Sanitation Hose at Defender

You'll also need to install a vent thru-hull a lot closer to the toilet. I wouldn't put it directly above the toilet, though...I'd find a location about a foot below toe rail that'll let you run a vent line a bit longer than it would be going straight up to keep the vertical rise below 45 degrees. And, I'd enlarge the vent fitting on the tank to use a 1" line and use a 1" open "bulkhead" thru-hull. That'll provide a lot more air exchange, which is the key to preventing odor out the vent.

--Peggie

Thanks. I have the dometic 975msd 5 gal holding tank potty. I was planning on using the sanitation hose you mentioned and a five eights inch inner diameter vent line which fits the MSD fitting to the holding tank. Thanks for the advice. I just think installing this potty will keep the system simple, and it makes for less possible things to go wrong in the future. Also, I like how the Porta potty has a looking glass to be able to see when it is full. With a marine holding tank we would have to get a sensor to do the same thing. We have used the Dominic porta potty (not with pump out though) on our Chrysler 26 and the potty works really well.

 

[Erbardy]

i went ahead and actually installed the marine head with a 17 gallon tank. I also purchased the list tank level sensor.