Black water tank in engine room?

[PaulRainbow]

Interesting. I plan to only use fresh water for flushing though. Having talked to a few live-aboards I've included a 750L fresh water tank in the bow - sounds like a lot to me but everyone complained about not having enough fresh water on board.

That's not as much as you might think. Living aboard on my own, during my refit, i empty my 340L tanks in a week, without using any for the toilet or shower (using the marina facilities and my toilet is seawater flush anyway). I'm not so sure of the wisdom of using your freshwater for flushing.

 

[Lomax]

That's not as much as you might think. Living aboard on my own, during my refit, i empty my 340L tanks in a week, without using any for the toilet or shower (using the marina facilities and my toilet is seawater flush anyway). I'm not so sure of the wisdom of using your freshwater for flushing.

Thanks, that's a very useful data point! Happier now with the space occupied by such a huge tank. Wrt fresh water flushing, from what I understand flushing with canal water can have very unpleasant side effects, smell wise - salt water is probably safer in this regard, but I suspect that it is the chlorine content in fresh water which causes the reported improvement.

 

[PaulRainbow]

Thanks, that's a very useful data point! Happier now with the space occupied by such a huge tank. Wrt fresh water flushing, from what I understand flushing with canal water can have very unpleasant side effects, smell wise - salt water is probably safer in this regard, but I suspect that it is the chlorine content in fresh water which causes the reported improvement.

I've only ever used salt water, so can't comment on canal water, i suppose in some places it could be an issue. Might be worth setting up to use either, via a changeover valve ? Have you looked into the composting toilets they are fitting on on some of the narrow boats ? Possibly an option ?

 

[Lomax]

I've only ever used salt water, so can't comment on canal water, i suppose in some places it could be an issue. Might be worth setting up to use either, via a changeover valve ? Have you looked into the composting toilets they are fitting on on some of the narrow boats ? Possibly an option ?

Might be an option, yes. I guess such a selector can be added later without too much trouble. It would have to include a pump, since the macerator type loos expect pressurised water for flushing. I have looked at composting loos, but they have two major drawbacks; firstly, all the ones I've seen are "dump-through" style, meaning you're sitting on the "tank", meaning the tank has to be inside the tiny bathroom - the ability to save space by placing the tank elsewhere is very valuable to me. Secondly, you still need to deal with the waste...

 

[vyv_cox]

I suggest you look at the Jabsco Lite toilets. They include a flushing pump and a macerator in a simple design. Ours works very well, consumption of water is quite low. We have had ours for something like seven years, still on the original belt, used for half the year by two people.

I would caution against using a single tank for domestic and toilet duties. There is no such thing as a perfect valve, you will always have some contamination.

 

[Momac]

I understand flushing with canal water can have very unpleasant side effects, smell wise.

Shortly after buying our first boat realise flushing with river water was causing a smell. Closing the seacock valve and using fresh water to flush solved that. I changed boats but still do the same. You can get a device that introduces some chemical into the intake pipe to cut out the smell if preferred..
In my case there is a shower and the shower head is on a long hose in the same compartment so use that for flushing the loo when required.
If you plumb in fresh water toilet flushing you must use non return valves -- but as suggested best have a separate tank. Then you can be fee of health risk and add some chemical freshener to the flush water.
We make use of shore facilities, which are usually available in our area. This way its pee only for our on board loo. Also bag up paper and use nappy bags for disposal which avoids any chance of blockages.
My waste tank only has an indicator when almost full. We have a fair idea when it must be getting somewhere near.

 

[Lomax]

I suggest you look at the Jabsco Lite toilets. They include a flushing pump and a macerator in a simple design. Ours works very well, consumption of water is quite low. We have had ours for something like seven years, still on the original belt, used for half the year by two people.

I would caution against using a single tank for domestic and toilet duties. There is no such thing as a perfect valve, you will always have some contamination.

Thanks for the recommendation, I've made a note of it. Though my ideal toilet would be a bulkhead mounted one, like the SaniMarin SaniStar. Rather pricey though! Which reminds me of another question; how does one deal with bilge access under the bathroom if it's been built as a wet room? I imagine one would have to have some kind of watertight tray on the floor, with a drain leading to a pump (a Whale Gulper has been recommended), but how can you make this removable/openable?

Interesting about the cross contamination hazard - I knew about needing a non-return valve but not that this might not be sufficient. How about using a small reservoir that is gravity filled from the main tank? I don't want to have to split my fresh water supply in two...

 

[Lomax]

Shortly after buying our first boat realise flushing with river water was causing a smell. Closing the seacock valve and using fresh water to flush solved that. I changed boats but still do the same. You can get a device that introduces some chemical into the intake pipe to cut out the smell if preferred..
In my case there is a shower and the shower head is on a long hose in the same compartment so use that for flushing the loo when required.
If you plumb in fresh water toilet flushing you must use non return valves -- but as suggested best have a separate tank. Then you can be fee of health risk and add some chemical freshener to the flush water.
We make use of shore facilities, which are usually available in our area. This way its pee only for our on board loo. Also bag up paper and use nappy bags for disposal which avoids any chance of blockages.
My waste tank only has an indicator when almost full. We have a fair idea when it must be getting somewhere near.

Yep, this is what I've heard from others as well (river water making a stink), hence my plan to use only fresh water for flushing. Also going to fit shower in the same room, with a trigger grip type shower-head (to save water). Will definitely take advantage of shore facilities whenever available too. Still haven't looked at tank sensors but would prefer one that gives a more gradual indication.

 

[vyv_cox]

Thanks for the recommendation, I've made a note of it. Though my ideal toilet would be a bulkhead mounted one, like the SaniMarin SaniStar. Rather pricey though! Which reminds me of another question; how does one deal with bilge access under the bathroom if it's been built as a wet room? I imagine one would have to have some kind of watertight tray on the floor, with a drain leading to a pump (a Whale Gulper has been recommended), but how can you make this removable/openable?

Interesting about the cross contamination hazard - I knew about needing a non-return valve but not that this might not be sufficient. How about using a small reservoir that is gravity filled from the main tank? I don't want to have to split my fresh water supply in two...

Sounds like a shower tray on many boats, but somewhat bigger and removable. A small bilge pump should cope with shower water.

A day tank for water should be OK but avoid having a dip tube for the supply, let the water fall from the top as in a domestic cistern. Non return valves are notorious for not closing immediately or permanently, particularly the ones on toilets, hence the H2S smell when they are used after a time at rest.