Desalinating for camping - your thoughts please?

[Reel Nauti]

Hi all

My wife, daughter and I love to go camping for extended periods of time, sometimes up to a month. We usually go to reasonably remote isolated places by boat, so everything we need has to go in the boat - 4.4 mtr Savage Jabiru. By far, the greatest burden and concern is always fresh water. At 1kg per litre it doesn't take a hell of lot for the boat to be loaded to the max.

I've been looking at small desalination plants - reverse osmosis - and have found that they are available for this sort of application and small units can produce 80 litres of fresh water per hour. At around $2000 they're not cheap, but some people would comfortably spend that amount of money on a week's holiday accomodation.

The unit I'm looking at only weighs 31 kg, and would easily run off the gennie. Has anyone ever used these things, do you think it's a feasible proposition?

I'd really appreciate your thoughts and comments please!

Cheers and thanks

Dave

[Dan5]

I used to look after one on a charter boat that i worked on,it was a lot larger in size than the one you are talking about though.It made 1500ltr's per day roughly,to keep your paper pre filter's clean for a while without having to chuck them out after 24hrs you still need clean saltwater.I backflushed usually twice a day and the unit did a self dump about every 5-6 hrs depending on maintained pressure.

Are you sure 80l an hour(1920ltr per day) for a 30 kg unit? the unit we had was fairly large and would have weighed a couple of hundred kg's with the pre filter etc.

I have seen a compact unit that was fitted to 42 ft cat but it was only rated at about 10ltrs per hr.

What make is the one you are looking at? the one we had was a M'cormack from memory.

Dan......

[tunaticer]

Is it possible to camp next to a freshwater spring and use a sand spear?? they weigh only a few kgs and you will have water on demand. Hell of a lot cheaper and more efficient for camping in the right areas.

Jack.

[FNQCairns]

As above a sand spear might be the go, it's extraordinary at times (often) just how close to salt water is a supply of freshwater.
Keep a close eye on what trees grow where and how close to the salt in the sand and example would be casuarina stricta?? trees bordering a beach.

cheers fnq

[johnny roger]

Is it possible to camp next to a freshwater spring and use a sand spear?? they weigh only a few kgs and you will have water on demand. Hell of a lot cheaper and more efficient for camping in the right areas.

Jack.
Gday tunaticer,

what is a sand spear? and how does it work?

John

[Reel Nauti]

The unit I'm looking at is a Schenker Smart 80ltr per hour. It consumes 32 amps on 12 volt, 16 amps on 24 volt, 1.8 amps on 240. 380 watts. It weighs 35 kgs.

I don't know a lot (bugger all) about sand spears, but I do know that taking the family away I must be able to rely on a water supply. Where we usually go there is no-one else around, no facilities, no nothing. Just us, the bush, the beach, the ocean, and a beautiful estuary system.

I'm just kicking the idea over at the moment. Just seemed like a reliable and efficient system that would save me carrying loads and loads of water. It's a lot of money, but if it is the bees knees it might be a sound investment? Set up the camp, place the inlet in the briny, plug her in and....presto!! Could it be that easy? I was only looking to run it as we needed water, probably in 80ltr lots. That's only 1 hour every 2nd or 3rd day.

I note your comments Dan and have checked the details again. They are available on the net, but I do need to do more research on the filter replacement etc. Thanks for your help.

Can I assume no-one has one for camping or not hired one?

Cheers and thanks for the input

Dave

[Reel Nauti]

Is this REALLY expensive, considering some would pay nearly that much for an engel + batteries + chargers etc, or other sort of refridgeration system.

When there is no fresh water to be had, yet you're surrounded by the Pacific,...... water water everywhere and not a drop to drink! What has stopped people having one of these things? Is it the cost?

Dave

[tunaticer]

http://motorcare.com.au/sspear.htm

They are good and depending on the water table you are accessing it can beas good as filtered water.

Jack.

[Reel Nauti]

I'll check them out. Thanks Jack.

[Simmo2]

Mate I have never used one, although for extended trips your idea does have merit.
One thing I would consider though, is that drawing 32amps is going to take a hell of a lot of recharge for the batteries. How would you recharge them??
Also, big batteries can weigh in at 60 kilo's each, again a lot of weight.

[Reel Nauti]

Yeah Simmo batteries would take a flogging that's for sure. I was thinking more along the lines of running the unit from the generator. Taking 380 watts a 2 KVA gennie would handle it without a problem, I think.

I'm going to look into the sand spears, but just a little concerned about the "what if" I can't find water. The desalination would surely be something I could depend on, and reading about them it states that they can also be used for brackish or stagnant water, dam water, even urine.

The island we camp on has no dams, and I've not seen any evidence of fresh water. Having said that, there is an abundance of wildlife, including dingo's, roos etc etc, so they must be getting fresh water from somewhere. There might be a little hole somewhere, and that would suggest underground water. Jack's recommendation of the sand spear is also something I am going to look right into.

Thanks

Dave

[station-rat]

Sand spears will work in the right suitation, but you can't tell whether the water is drinkable (bacteria levels are a problem in some places) Reverse osmosis solves this problem. Might be expensive but they work

[SeaHunt]

If you take enough beer you don't need water;D

[bungie]

Ever thought of going this way ??

http://www.konia.com.au/

[Reel Nauti]

Bungie I didn't know any such thing existed! I have looked at the site and flicked them an email requesting more info. Thanks for this, it might be a terrific option.

Cheers

Dave

[PADDLES]

dave, the thing to consider with the konia product is how long it will take to collect the water. the reverse osmosis unit you're looking at should be able to desalinate water much quicker so you have to run your genny for heaps less time.

[Reel Nauti]

I sent an email to Konia and received a very vague reply from the manager who just stated that it is early days and the research is still developing. The only question he specifically answered was that the unit requires 500watts. He did not answer anything else regarding amount of water produced, time taken, etc etc. According to their website the product is on the market..................strange that the manager can't answer specific questions????????

Dave

[Reel Nauti]

I have just now phoned the manager of Konia, and might I say that I was extremely disappointed with his attitude. The facts are:

The water is produced a drop at a time.

Small units can produce 23 ltrs per 24 hrs, the largest unit can produce around 80 ltrs per 24hrs.

Cost of the small unit is around $1000.00 and that is just to produce raw water.

Filtration units can cost hundreds of dollars on top of that.

The units draw 580 watts.

My summary is that this would be an extremely expensive and arduous method of making fresh water. Further, due to the huge consumption of power required I can not comprehend how they could possibly be 'environmentally friendly'.

It was an alternative worth exploring and thanks for the suggestion. The facts however present this method of water making as an alternative not worthy of further consideration under any circumstances - in my opinion.

Cheers and thanks

Dave

[PADDLES]

that's what i wondered dave, they seem to work on the same principal as a refrigerated air dryer on a compressor. ie, you run the air over a cooling element to condensate any moisture out of it. it might make a handy air conditioner for your tent ............... if you can handle the fuel bill for the genny :o

[Reel Nauti]

Yeah I sure as hell don't want to be running a gennie for those periods of time. What I save on carting water I'd be spending on bloody fuel!

I've still got more enquiries to make on the sand spear. If you can't be sure the water it produces is bacteria free then that would mean boiling the drinking water. That's not a real problem, but I'm still concerned about the possibility of not finding potable water, or it being too deep to reach. I have to know 100% without any doubt at all prior to leaving the boat ramp that I will have a water supply.

It is good to suss out all of these options and alternatives and I am really enjoying the learning experience. Others might learn from my questions and research into this topic as well and that is a good thing.

Thanks for everyone's input. I guess we have a way to go yet!

Dave

[Simmo2]

I am really enjoying the learning experience. Others might learn from my questions and research into this topic as well and that is a good thing.

Dave

Yep watching the developments in this thread with interest too.
I have a mate thats a water driller for the NT gov. I have asked him some questions via sms, but he's yet to reply.

[team_mongo]

Dave,
have a look at katadyn powersurvivor desals. They are very light 11-15kg, and use very little power. The smaller model makes 5L/hr and uses 4A on 12V, the larger makes 12L/hr and uses 8A on 12V. Could easily be supplied by solar panels.

Just need to work out how much water you need.

George

[Reel Nauti]

Thanks George

The Katadyn product certainly looks appealing, particularly the Power Survivor 160E. It produces about 24 ltrs an hour. I could run it for a few hours which would give me enough for my wife and I for a few days, and that would also give me time to recharge the batts. Looks good!! I have sent them an email requesting further details and prices. Will keep everyone posted.

Cheers and thanks

Dave

[FNQCairns]

If all fails you could consider a simple campfire/gas distiller, easy to make and reliable even with salt water.

Look forward to hearing about the 160e.

cheers fnq

[Reel Nauti]

HI FNQ

How long would it take to produce 20ltrs of fresh water. Boiling point is boiling point I think, so the production can't be hurried? I did consider something like this but thought it would be an all day job? Can you elaborate further please mate?

Cheers

Dave

[FNQCairns]

Hi Mate the one I had to do with was made out of a pressure cooker, aluminum pipe (connected to where the removed pressure valve was) which once away from heat then had rubber hose attached with a diffuser on the end made of metal that dumped into a 20L steel drum with a couple L of clean starting water in it.

The trick is catching as much of the gas as possible, this unit worked real well once the rescued water got up a bit as all of the water condensed out due to the diffuser underwater not at all like a moonshine making design etc.

We did 2, 5L batches on gas and it was fast, was a mates design and work, in this test we tainted the condensed water as it boiled to violently and splashed the exit, due to the pressure cooker design the steam forced splashed dirty water away with it, later i understand he affixed a small expansion chamber to the top after which the alum tube came off and that solved the problem I think.

20-30min per 5L once boiling if i had to make a guess now so real fast compared to what you are thinking.

Dunno if too much info but if you are handy it could make a good project i suppose?

Cheap too:)

I have also heard of old metal jerry cans being used with rags to seal and radiator hose sized pipe as the take off but it would be pretty inefficient as only drips could be caught most of the steam would escape depending on hose length.

cheers fnq

[Reel Nauti]

I've got a 55 ltr stainless keg that could probably be easily converted into something like you have said FNQ. I'll look into this further as well.

Thanks mate

Dave

[MEGA'bite]

station- rat sand spears filter down to 1 mycron, not to mention all the water you are getting is filtered thu natures best filter, SAND .

[Simmo2]

I've got a 55 ltr stainless keg

Yeah, but then you need to cart gas, a tap...and not to mention schooner glasses!! ;)

[skipalong]

they cant go very deep can they

[alfish]

station- rat sand spears filter down to 1 mycron, not to mention all the water you are getting is filtered thu natures best filter, SAND .

how does this level of filtration compare to "katadyn" filtration quality, as i,ve used this type on very suspect water (as in cholera and dysentery) and come through unscathed.

ignore this question as i just checked out the info available here http://www.katadyn.com/water-knowledge/technologies.html

combine a sand spear with filtration to 1 mycron with a ceramic katadyn filter and you will have some of the purest potable water available. with pre filtering to to 1 mycron you will have very little maintainence on your ceramic filter.

al

[Reel Nauti]

Just an update on this..............I have written twice to Katadyn and not received any response whatsoever. This is a shame, as the product really looked the goods. However, it seems clear they are not interested in my business nor me being able to inform the 25,000 or so members of Ausfish.

Cheers

Dave

[team_mongo]

Dave,
sorry to hear about the poor response.

They have a dealer in Oz McIntyre marine down at the Gold coast city marina, coomera. Ph 07-55736611 Fax 07-55029777 Give them a bell..

There is also a complete self contained setup - spectra aquifier 150 (complete with battery and/or solar panels) but not cheap - around $10k.

George

[fish_outta_water]

hiya mate
just wondering if youve thought about the option of building a small still , i assume youve already got a stove and pans , all youd need is a conical lid and spiral copper tube , would provide enouh water for drinking and cooking , depends how much ya need though
carl