Tanks.How much do I really need?

Two adults cruising, with four people, two adults and two children, occasionally.We will be out for a week at a time,7 day week.Two days will be spent off boat sight seeing,just spending nights aboard.How much tankage would you need for fresh water used to flush potti,shower,and do dishes occasionally.We drink and cook with bottled water when on the boat.What ratio do you use when considering black and grey water tanks?I'm thinking something like,100 gallons fresh,60 gallons grey,and 60 black.What say ye?How much water does your vessel use over a full week?

Hey Ben. There are so many factors it is hard to say how much YOU need. I will say for us, we do not have a gray water tank so that is one less thing to worry about... We have 150 gal fresh and 30 gal holding. with the two of us we have easily gone four days at anchor with plenty left but we are from California and happy to skip a shower and follow the "if it's yellow, let it mellow" type water conservation methods. One of our friends stretches his fresh water by taking sunshowers to a nearby marina and filling them from a spigot, to use those for showers instead of his tank water.

Maybe someone has a scientific way of calculating. I know Peggy Hall had a formula for how much water is typically used per flush and that was a factor in our decision in the size of our holding tank, though we were limited by the space available...

We carry 170 gallons of fresh water (which we drink) in two 85-gallon stainless tanks in the lazarette. The forward head is connected to an approx. 40 gallon holding tank in the engine room. The aft head is connected to a 25 gallon tank in the lazarette.

Our toilets are salt water flush so there is no fresh water demand there.

There are generally just two of us on board although we occasionally take two adult guests for two-week cruises into BC. 170 gallons of fresh water has been more than adequate although we generally top the tanks off once in a two-week trip. Not because we're particularly low but because we don't want to be.

The 40 gallon holding tank for the forward head has proven to be adequate for a pair of guests on our longer cruises although we usually dump it once during that period. The 25 gallon aft holding tank is not adequate for the aft head but there is no space for anything larger.

If you are trying to get a one-week capacity out of your tanks I would think that the 60 gallon black water tank would be pretty good. With kids and fresh water toilets I would probably rethink that 100 gallon fresh water capacity, though, and increase it by a fair amount if you can.

I can't offer any suggestions on gray water since most boats including ours don't have or need these up here.

We use 15-20 gallons of fresh water/day with 2 adults and a dog. We have a Vacuflush head, shower every day and normal dishes. The dog gets rinsed after every beach walk. Clothes and boat washing usage aren't included.

Can't help you on the black or grey water tanks.

FWIW, I think 100 gallons of freshwater is def light on, I would double that if you can, grey water no idea, black water 60 gallons would be good.

Ben , why do you use bottled water to cook with?, is the tap water in your part of the world that bad?

On the boat our grey water goes overboard so carrying it isn't an issue. On our bus we carry everything. We have 100 gallons fresh, 20 gallons drinking water, 100 gallons grey water and about 40 gallons black. The grey always fills up first. We're two adults who are accustomed to conserving water. We can go 10 days if we're really careful. I know people who claim to go longer on that amount of water but I wouldn't want to do it. For sure you'd smell really bad because after 10 days we're getting close to ripe.

Thanks for the help.What do you all do about grey water,over board?That's something that isn't allowed here.Well,not within a certain distance of shore.I doubt I will ever be more than a mile off shore,except for the gulf crossing on the Great Loop cruise.

Black water is not allowed to be dumped overboard in the inside waters of Washington State. Overboard dumping of blackwater is allowed in British Columbia in areas that have not been designated no dumping zones. The no dumping zones for blackwater tend to be harbors, marine parks, bodies of water that have a low water exchange rate, and so on.

Gray water is not an issue at all up here. I'm rather surprised to hear it is in your area. So our sink drains and shower sumps simply go by gravity or pump overboard via through-hulls.

bobofthenorth said:

On the boat our grey water goes overboard so carrying it isn't an issue. On our bus we carry everything. We have 100 gallons fresh, 20 gallons drinking water, 100 gallons grey water and about 40 gallons black. The grey always fills up first. We're two adults who are accustomed to conserving water. We can go 10 days if we're really careful. I know people who claim to go longer on that amount of water but I wouldn't want to do it. For sure you'd smell really bad because after 10 days we're getting close to ripe.

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The kids and myself will probably spend a fair amount of time in the water,so we probably won't shower everyday.When we do the great loop,it will be my girlfriend and our son.My oldest son won't go with us.We will use shower facilities where available.I will do a week on one of our large local lakes to get an idea of what I may need.I just need a starting point and I think i have that.

Marin said:

Black water is not allowed to be dumped overboard in the inside waters of Washington State. Overboard dumping of blackwater is allowed in British Columbia in areas that have not been designated no dumping zones. The no dumping zones for blackwater tend to be harbors, marine parks, bodies of water that have a low water exchange rate, and so on.

Gray water is not an issue at all up here. I'm rather surprised to hear it is in your area. So our sink drains and shower sumps simply go by gravity or pump overboard via through-hulls.

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My shower will be close to water line so I would need a macerator pump to go overboard.I will check the grey water regs again to be sure.I know our lakes don't allow anything over board.I could add a ball valve and divert when not on the lakes.

ben2go said:

My shower will be close to water line so I would need a macerator pump to go overboard.I will check the grey water regs again to be sure.I know our lakes don't allow anything over board.I could add a ball valve and divert when not on the lakes.

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You don't need a macerator pump to pump a shower sump overboard. You do need a pump that won't get clogged or wound up with hair. The most trouble-free kind of shower sump pump is a diaphragm pump like a Whale Gulper.

But I did not realize you are boating lakes so I guess that presents different regulations and requirements to what I'm used to on salt water.

ben2go said:

Thanks for the help.What do you all do about grey water,over board?That's something that isn't allowed here.Well,not within a certain distance of shore.I doubt I will ever be more than a mile off shore,except for the gulf crossing on the Great Loop cruise.

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Except for a lake or two...99.9 percent of the places you go allow grey water directly overboard...certainly 99.9 percent of the great loop.

Marin said:

Black water is not allowed to be dumped overboard in the inside waters of Washington State. Overboard dumping of blackwater is allowed in British Columbia in areas that have not been designated no dumping zones. The no dumping zones for blackwater tend to be harbors, marine parks, bodies of water that have a low water exchange rate, and so on.

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This is no longer true but it probably deserves a separate thread. So let's just say this information is wrong as of May 2012 and I'll start a new thread.

Marin said:

You don't need a macerator pump to pump a shower sump overboard. You do need a pump that won't get clogged or wound up with hair. The most trouble-free kind of shower sump pump is a diaphragm pump like a Whale Gulper.

But I did not realize you are boating lakes so I guess that presents different regulations and requirements to what I'm used to on salt water.

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I didn't think about a diaphragm pump.It's been a while since I worked on a boat or RV with facilities.I thought I mentioned lakes.I will be on lakes and ICW along with planning a couple Great Loop trips.Since the boat will do the loop,I want to set it up for that and I will be covered for most anything else I will do.

psneeld said:

Except for a lake or two...99.9 percent of the places you go allow grey water directly overboard...certainly 99.9 percent of the great loop.

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I will make sure to check regs for updates, but the lakes I go to don't allow any over board discharge.

bobofthenorth said:

This is no longer true but it probably deserves a separate thread. So let's just say this information is wrong as of May 2012 and I'll start a new thread.

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Thanks for clearing this up.Please post a link to your thread in case we miss it.

Showers and dish washing are the big water wasters.

This is LEARNED behavior. And with practice a great shower can be had with 2 or 3 gal of water.

The solar plastic bag showers work well, or if its cool an old pump fire extinguisher holds about 2 gal, and can be stove top heated.

For rinsing dishes use a 1 quart pitcher ( 1 pint is even better!).

In most lakes the lake can be your supply , a simple wash down pump and cockpit showers isn't bad in summer..

Discharging waste is only a problem with cheap pumps , look for an Obendorfer (what is the heart of the usual dockside units) 10-20 years of service , but you pay up front for the pleasure of NOT repairing/replacing a black pump endlessly.

http://www.oberdorfer-pumps.com

FF

Pineapple Girl said:

............the "if it's yellow, let it mellow" type water conservation methods. ..............

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While that' an OK policy at home if you need it, it's generally a bad idea on a boat.

Why? Because on a boat, you typically have hoses, not pipe leading away from the head. Left for long periods filled or partially filled with urine, the hoses will become permeated with odor and stink up the boat.

It's important to use enough flush water to move any sewage out of the hoses and into the holding tank.

My wife and I will often share a flush. Two uses, one flush.

ben2go said:

Thanks for the help.What do you all do about grey water,over board?That's something that isn't allowed here.Well,not within a certain distance of shore.I doubt I will ever be more than a mile off shore,except for the gulf crossing on the Great Loop cruise.

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"Grey water" is what's left from showering, washing hand and dishes, etc. Only a few lakes in the USA prohibit draining grey water overboard. It's perfectly OK in coastal waters.

"Black water" is what goes through the head. Pee, pooh, and flush water. That's what is regulated everywhere in the USA.

rwidman said:

While that' an OK policy at home if you need it, it's generally a bad idea on a boat.

Why? Because on a boat, you typically have hoses, not pipe leading away from the head. Left for long periods filled or partially filled with urine, the hoses will become permeated with odor and stink up the boat.

It's important to use enough flush water to move any sewage out of the hoses and into the holding tank.

My wife and I will often share a flush. Two uses, one flush.

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I agree with Pineapple girl...but the again I have an RV toilet where it stays in the bowl...not the hose

Then again.... I don't think an hour or so till the next use is going to saturate any hose that much faster...lets see what she says about hose permeation.

If you really need to conserve fresh water install a foot pump for the sink.

Guests not acustomed to carrying water often think like they are at home.

If you have to pump it you won't leave the water running.

I have also seen a little contraption for the faucet. Looks like a stick hanging out of the faucet. You have to move the stick for the water to run. Let it go and the water stops. I don't know what it is called.

SD

Is this what you mean, SD?

http://ecx.images-amazon.com/images/I/31HcUwOkZRL._SL500_AA300_.jpg

I got one of these from our water company for water conservation at home. I installed it on our two-handle galley faucet a year ago. This way we can set the temperature with the separate hot and cold handles and then toggle the water on and off as we need it for hand washing or dishes. I don't know how much we save, but I like not having the water running when it's not needed and not having to reset the temp every time I turn it off for a few moments.

Amazon.com: Kitchen Faucet Aerator On/Off / Water Saving Swivel Spray Stream 1.50 gpm: Kitchen & Dining

ben2go said:

The kids and myself will probably spend a fair amount of time in the water,so we probably won't shower everyday.When we do the great loop,it will be my girlfriend and our son.My oldest son won't go with us.We will use shower facilities where available.I will do a week on one of our large local lakes to get an idea of what I may need.I just need a starting point and I think i have that.

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If you are in salt water, you will need to shower or at least rinse off afterwards. Same for some fresh water. This water is not as clear and clean as it may be in your local lake.

ben2go,

As I read your various posts, I am confused. Do you already have a boat that you plan on cruising in or are you planning on buying one? Or are you building or rebuilding one?

Usually, when you buy a boat, tankage and your other concerns have already been designed into the boat by the builder, taking into consideration the probable intended uses of the boat.

FF said:

Showers and dish washing are the big water wasters.
We won't be washing many dishes,couple pots and pans.Everything else will be plasticware.

This is LEARNED behavior. And with practice a great shower can be had with 2 or 3 gal of water.
In RVs I install those shower heads with the pull string to allow water to flow.When the string is released,the water stops flowing.I don't remember the manufacture right off.

The solar plastic bag showers work well, or if its cool an old pump fire extinguisher holds about 2 gal, and can be stove top heated.
I have used a 2.5 gallon chemical sprayer as a shower when land camping.Let it sit in the sun about 30 minutes and it's ready to gf course we have them dedicated to this and no chemicals have been used in them.


For rinsing dishes use a 1 quart pitcher ( 1 pint is even better!).
Never thought of that.I just fill the sink with about a gallon of water and use a rag to help rinse.


In most lakes the lake can be your supply , a simple wash down pump and cockpit showers isn't bad in summer..
I've used those outdoor showers on an RV a friend had.Powered by the water hook up and not off the self contained water tank.


Discharging waste is only a problem with cheap pumps , look for an Obendorfer (what is the heart of the usual dockside units) 10-20 years of service , but you pay up front for the pleasure of NOT repairing/replacing a black pump endlessly.

Rotary Gear Pumps, Mag Drive Pumps, Centrifugal Pumps, Rubber Impeller Pumps by Oberdorfer Pumps a subsidiary of Gardner Denver
Thanks.I will have a look at those.

FF

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rwidman said:

"Grey water" is what's left from showering, washing hand and dishes, etc. Only a few lakes in the USA prohibit draining grey water overboard. It's perfectly OK in coastal waters.

"Black water" is what goes through the head. Pee, pooh, and flush water. That's what is regulated everywhere in the USA.

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Yep.Very familiar with those terms.

skipperdude said:

If you really need to conserve fresh water install a foot pump for the sink.
I had not thought of that,but I have used them in some boats.


Guests not acustomed to carrying water often think like they are at home.

If you have to pump it you won't leave the water running.
True.Make'em work for it.

I have also seen a little contraption for the faucet. Looks like a stick hanging out of the faucet. You have to move the stick for the water to run. Let it go and the water stops. I don't know what it is called.
I know exactly what you are talking about but for the life of me I don't remember what they are called either.
SD

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rwidman said:

If you are in salt water, you will need to shower or at least rinse off afterwards. Same for some fresh water. This water is not as clear and clean as it may be in your local lake.

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I can agree to that.

rwidman said:

ben2go,

As I read your various posts, I am confused. Do you already have a boat that you plan on cruising in or are you planning on buying one? Or are you building or rebuilding one?

Usually, when you buy a boat, tankage and your other concerns have already been designed into the boat by the builder, taking into consideration the probable intended uses of the boat.

Click to expand...

I am planning a build for spring 2014.Trying to get a good close approximation as to how I want the boat set up,so I can work with the designer to accommodate tankage and placement.

for what it's worth I've got 1,000 gallons of fresh water. Never can have enough. My rv tank is about 30 and we run out of that in about a day. If we use bottles to drink (beer bottles for me) and take quick showers we can stretch it to a few days. Has anyone tried building a solar water heater. Similar to a pool water heater?

ron, the guys at tht miss you! They started a thread wondering what happened to you. I told them you jumped ship.

FF said:

I am planning a build for spring 2014.

With the price of used boats hammered as they are, what requirements do you have that would not be met by a used boat at 30% the cost?

FF

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Width,height,weight,draft,space,fuel efficiency,and ability to trailer without special permits behind a pick up.Plus, I can build cheaper than buying used.The bartering system here is very strong since the economic crash.It is quickly improving and we are no longer close to number one in the country for unemployment.


Here is my issue with the boats I have been checking out.The wood stringers and transom are usually soft which means rot.All the flotation foam is water logged.Most need serious structural repair before taking on a long cruise.I have repaired these problems on boats before.It easier,cheaper,and faster to build from scratch.Another issue is weight and size.I looked at an older,late 80's cruiser,that was built like a knock off Bayliner.It was 25'4" LOA with an 8'4" beam.Weight was over 10,000lbs on the lift.Height from water line was almost 15' to the fly bridge top.all the tanks were empty except 1/4 tank of fuel.I want something larger.Most boats over 27 foot have to be hauled behind a rig and need oversize permits for width and height.I want to avoid these issues.

Well I guess I might might as well throw in my $0.02.
There are two of us living on our 45. We have a Vacuflush system that uses fresh water into a 50 gallon holding tank. Our freshwater is two tanks for a total of about 200 gallons.
We can get 7 days on the black water tank and the fresh water.

As indicated there are so many variables that will make everyone's answers so different. They type of flushing system you have, vacuflush or electric or hand pump. Fresh water or raw water. How often you shower, Navy shower or regular shower and how often.

Papa Charlie said:

Well I guess I might might as well throw in my $0.02.
There are two of us living on our 45. We have a Vacuflush system that uses fresh water into a 50 gallon holding tank. Our freshwater is two tanks for a total of about 200 gallons.
We can get 7 days on the black water tank and the fresh water.

As indicated there are so many variables that will make everyone's answers so different. They type of flushing system you have, vacuflush or electric or hand pump. Fresh water or raw water. How often you shower, Navy shower or regular shower and how often.

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An incinerating toilet was suggested to a member of another forum.I have heard of these but have avoided them due to my ignorance of them.I understand a little about the home style,but honestly not enough to make an informed decision on one.

I have been reading up on electric and vacuflush.I know a good bit about electric units used in RVs.I'll keep studying.

I think I can get away with 50g black and 50g grey for our week long lake trips.I've decided to include a diverter on the grey water to pump over board.I am really trying to keep the thru hull fittings to an absolute minimum.

I don't always shower everyday,my son don't either.My son and I can take a wash down on deck in our short pants.The misses has to have a bathroom.I did find a collapsible shower stall for deck showers.Maybe an option in the summer.