San-X Replacement Project

As some of you saw in another thread, Washington State is implementing a NDZ in Puget Sound. Our boat came with a SanX Type-I treatment system as a workaround for a failed and now decommissioned stainless steel belly holding tank (pinholes, failed drain fitting = yuck).

Knowing this new rule would impact our boat we had originally planned to replace the SanX with a holding tank, so the May 10th implementation just accelerates our timeline.

The plan is to install at least a 20 gallon but up to a 40 gallon tank in the space currently occupied by the SanX. This allows us to reuse most of the plumbing systems that are already in place.

So far I've found three bow tank options:

20 Gallon Bow Tank
30 Gallon Bow Tank
40 Gallon Bow Tank

Both the 20 and 30 will fit the space easily. The 40 will also fit, but I'll need to remount the genny (our generator is in the forepeak under the v-berth) about 3" aft from it's current position - which isn't a huge deal but it's extra work.

My ideal scenario would be to install the 40 to maximize our flexibility in terms of days between pump outs and because we'll use the boat as guest overflow in the summer (up to four aboard for a week). We do have a pump-out-boat in South Lake Union which makes this easier, but it's usually on a weekly schedule.

I plan to document the change over here and on the BlueWater 40 FB page in case anyone else has a similar situation.

Two of us live on the boat full time and we get 7 days with one head and a 30 gallon tank. I can stretch it a few days but ....

Thanks Larry, great info.

Also, I should've mentioned, we have a single head with a VacuFlush followed by a macerator in line before the SanX then another Macerator between the SanX and through hull (I assume this one was original to the factory holding tank).

Our head is a VacuFlush with no macerator.

Greetings,
Mr. 345. Put in the 40 gal. It only takes one flush to overflow at the worst possible time. Don't ask me how I know... My $.02.

Normally I'd ask where the head is located in the boat--how far from your proposed tank in the bowl. But you have VacuFlush toilets, so the question becomes how far from the vacuum pump? And is the vacuum pump further or closer to the toilet bowl than that?
'Cuz the suction only gets the flush TO the vacuum pump...it has to push it the rest of the way to the tank, and will only run till the prescribed amount of vacuum has been achieved. So if the run from the pump to the tank is longer than the run from the toilet to the vacuum pump, the pump will shut off before the flush makes it into the tank.

Everything is located quite close to each other (from head to the forward edge of the SanX is no more than 8'). The VacuFlush is within 3' of the head and maybe 4' from the SanX. A replacement tank will shorten the distance to the tank.

In our case, the VacuFlush feeds a macerator which currently pumps through a Y-Valve either overboard or to the SanX tank. The SanX then feeds down to another macerator which Y's into the overboard plumbing.

It took me a few tries early on to sort out what was installed and how things routed.

Is the vacuum tank and vacuum pump (or "vacuum generator") still installed, with a macerator pump added after the vacuum pump? Or is the macerator pump now the only pump between the toilet and the SanX tank? Or are you calling the "vacuum generator" a macerator?? 'Cuz the V/F isn't a macerating toilet!

Do you have an owners manual for it? Or any literature that shows a schematic of a VacuFlush? If not, I can send you one if you want to send me a PM that includes your email address (can't attach anything to a PM). Before you install a new tank, you really need to know what you actually have and take care of any maintenance on it.

And btw...the SanX was discontinued more than 10 years ago...no parts have been available for it for at least that long. TDX, a really nasty formadehyde based witches brew, is the only chemical certified for use in it as a Type I. It's still available, but if you're not using it, you don't have a legal Type I...so you're not really losing anything by replacing it with a tank...you're just finally gonna have a system that would have been legal before the new NDZ.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

HeadMistress said:

Is the vacuum tank and vacuum pump (or "vacuum generator") still installed, with a macerator pump added after the vacuum pump?

Click to expand...

Yes, vacuum tank/pump > macerator > SanX

HeadMistress said:

Do you have an owners manual for it? Or any literature that shows a schematic of a VacuFlush? If not, I can send you one if you want to send me a PM that includes your email address

Click to expand...

Thank you for the offer however we do have the manuals for the SanX. The PO was meticulous about records.

HeadMistress said:

And btw...the SanX was discontinued more than 10 years ago...no parts have been available for it for at least that long. TDX, a really nasty formadehyde based witches brew, is the only chemical certified for use in it as a Type I. It's still available, but if you're not using it, you don't have a legal Type I...so you're not really losing anything by replacing it with a tank...you're just finally gonna have a system that would have been legal before the new NDZ.

Click to expand...

Yeah, the folks at Marine Sanitation in Seattle were really helpful in educating me on SanX, the history, the law, etc. shortly after we bought the boat.

Completely agree on replacement. The holding tank work around was noted on our survey so we always planned to replace the tank, the NDZ date just moves that up on the list of things.

I would've loved to have replaced the original tank in it's current position but removal/installation of a new tank would mean the head bulkhead as well as a section of floor would need need to come out, so a bow tank it is.

Really appreciate your expertise and advice on our project. I'll try and post a picture of the entire system, end-to-end to document it, surface additional issues and show others the before and after.

TF members rock!

go as big as you can .we had a 15 on our last boat and it would not last a long weekend with two couples .that was mostly just the females using it. there were some adult beverages involved .our marina only did pump outs on Wednesdays so when we where there for the week we had to come back to the marina Tuesday and wait for the pump out Wednesday to go lack out on the lake. I don't know how the 30 will hold up .

wow Larry you have it down to a science. no way I could get our usage that low .

I was asking if you have the owners manual for the VacuFlush. The SanX is a separate system into which flushes go, same as they would to any holding tank.

There should not be a macerator pump after the vacuum pump.
Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

With a plan to occasionally use the boat for guests, I’m with RTF on getting the largest capacity possible. Guests often don’t have any idea how many flushes they do, let alone how much water it takes per flush. I have a 35 gallon tank and it’s been filled in 24 hours by two guests aboard. Additionally, don’t be surprised what you might find in a guest provoked clog.

We have a 40 gallon tank and I would put in a larger one if I had any possible room. The boat originally came with a 20 gallon tank and the PO replaced it and put as large as would fit.

healhustler said:

With a plan to occasionally use the boat for guests, I’m with RTF on getting the largest capacity possible. Guests often don’t have any idea how many flushes they do, let alone how much water it takes per flush. I have a 35 gallon tank and it’s been filled in 24 hours by two guests aboard. Additionally, don’t be surprised what you might find in a guest provoked clog.

Click to expand...

Agreed. We have a rule onboard: "You clog it, YOU clear it". I've ordering a placard to go over the head, right next to a box of latex gloves. I figure they'll get the message.

I have a page listing the equipment on the boat and where it is located that I give out to each guest that comes aboard. On the bottom of the page are directions about using the head. This usually provokes a discussion about how to use the facilities and the last thing on the list is a note that if you make a mess, you must clean it up. Haven’t used the latex glove idea, but it is a good idea...

Latex gloves, hmmm. Sounds good but I’m afraid they would just flush them down with everything else.

I made a lot of progress on the tank replacement this weekend and now have a functional holding tank. Once I decided on location (based on a similar setup in another Bluewater we decided it would go under the Pullman Queen bed in the master stateroom) and I mentally prepared myself to cut or drill new holes in bulkheads, the deck and the hull it actually went pretty well. The hardest part was routing the hose behind the head cabinetry, under the head and through the forward bulkhead (the Vacuflush is located forward of the head).

I still need to strap the tank, install the level sensor, remount and reinstall the existing Y valve and decommission and remove the San-X and the original (failed) holding tank. I think I’ll rebuild the Vacuflush pump and head seals next as it's cycling on too often.

All in all about an 8 hour install. Half of the time was spent planning and going back and forth to fisheries supply.

Wow Great Progress!!