Retrofitting Waste Holding Tank

[mgraham49]

My 1974 Peason 10m needs a holding tank, badly, just moved to an inland lake. Questions. (I) West marine and my local shop seem to say " just put the pump out fitting on the bottom". That just cannot be a good idea. But if on top, then I think it has to have a pickup tube, but I don't see anything about pickup tubes in the holding tank sections in West Marine from Todd, etc. Am I missing something? (ii) West marine said I needed a macerating toilet. since I don't have pressure water, this is getting really expensive. But do you need a macerator to keep the solids from getting stuck (biological solids). or will my WC Headmate head do the job. (iii) how important is the filter on the vent hose and (iv) has anyone used one of those oxygen pump bubblers to keep odors out (Sweettank is the name i think). Thanks to all

Mike Graham (sorry if this is too long, someone tell me if I should have only posted part at a time.

Mike

[sailingdog]

From my previous response to your other post on this subject in another thread:

The cleanout has to be on the bottom of the tank to drain the tank properly—if it was on the top of the tank with a pickup hose, it would have to leave a inch or two of standing sewage in the tank when you pumped out the tank. This would form a solid layer of crap on the bottom of the tank in relative short order, necessitating a tank replacement—unless you were willing to dig the stuff out manually. . The hose from the head usually enters the tank at the top or fairly high up so that the head doesn't have to pump against the contents of the tank and that the tank won't siphon back into the head bowl if your joker valve fails.

If you want a toilet that won't clog easily and doesn't use electricity, the best one to install is a Lavac. They're pretty bullet-proof, but are fairly expensive. They are plumbed slightly differently than a typical marine head as they use vacuum to evacuate the bowl, not a standard dual-action piston pump. Many cruisers like them because they're very low maintenance and relatively problem free and use less water than many other designs do.

The Headmate should work just fine with a holding tank. You don't need a macerator pump.

Putting a filter on the vent hose is a bad idea IMHO. The filter will reduce the air flow, reducing the flow of oxygen to the holding tank and promoting the stinky anaerobic bacteria. The oxygen bubblers are a waste of money, provided the tank is properly vented.

[duffer1960]

Your headmate will do the job. You don't need a macerator or pressure water. I know it sounds nasty, but the pump in the headmate will suck the stuff right up and and push it through the tube to the holding tank with no problem. This is standard. I assume it already is hooked up to a seacock to get it's flush water?

[mgraham49]

I rededicated the head seacock to be supply for the reverse cycle AC pump (thank you Lord, after 32 years of heat in Texas, for reverse cycle AC at the dock at night). So I have just been pumping freshwater into the sink, which drains into the head. someone told me freshwater was better for the holding tank, but I am now on a fresh water lake anyway.

I think I can do a "T" off the seacock, with a backflow preventer and maybe a ball valve to open if I need to go back to raw water for the head. I was concerned that the pump for the AC would suck air backwards through the supply line to the head otherwise (does that make sense?)

[mgraham49]

On the valve on the bottom, doesn't that leave you in a really messy position if you have a hose or clamp failure? I looked at a self contained unit from sealand that is 28 gallon, has eventhing installed, including a pump out pump. first, if I cannot discharge over the side, is there ever a time that the discharge pump would be used? I have never hooked up to a waste station, so I don't know. It looks expensive, but can be bought for about $650, and seems to have everything, including monitor lights, pump, etc. I don't mind spending the extramoney on this to get it right if that is the answer, it is going right under where I sleep, so I would really like it to not be stinky.

Or am I overengineering.

Mike

[duffer1960]

Yes, it is a mess if there is a failure, but that probably won't happen.

I get my flush water from the same line that the sink drain is attached to. For some reason, maybe because the T in the line is below the waterline, I never suck any air from the sink drain when flushing. This came in handy once when all of the water blew from the west end of Lake Erie where we keep the boat (the water level dropped 50 inches, yes you read correct 50 inches) during one storm and the hull ended up resting in the muck on the bottom of the marina. Needless to say, the only way to flush the head was to fill the sink before pumping.

As long as there is a pump out station area nearby, you won't need your own pump. The pump-out station is a giant poop sucking vacuum that sucks the tank empty. Check out this link: Installing a Head by Don Casey

There is another one by Peggy Hall, the HEADmistress. You can find her on Sailboatowners.com. I think she also has a book.

[TrueBlue]

Mike,
I've always found Peggy Hall's articles and books to be very informative. She's commonly referred to as "The Head Mistress". This ARTICLE might give you some answeres to your questions.

[TrueBlue]

While typing, duffer posted similar info before me.

[wchevron]

i agree with trueblue & duffer, go to sailboatowners.com and email peggy. she helped me out immensely and is quite knowledgable. i also bought her book which is really helpful.

[mgraham49]

For those who are wrestling with this, I spent some time on the telephone with Sealand, both Factory and one of their third party installers that they referred me to. Their products all have top feed waste removal fittings, with tubes that go to the bottom. when you look at their diagrams, you probably wind up with less in the bottom with their tubes than you would with a bottom discharge because of run back from the hose, etc. they say it works fine, and are standard in SeaRay, etc, which I have always thought of as a pretty well built stinkpot. They confirmed no need for macerator, that the action of the wilcox pump and joker valve pretty much chops everything up. The installer said that there was one grand banks that he knew of that had the sweet tank systme (pumping oxygen to the bottom of the holding tank, sort of like keeping a fish tank oxygenated keeps certain bacteria from growing) and that it worked well.

Now to do the deed.

Mike Graham