Natural swimming ponds in Thailand

[xye]

I searched within the ThaiVisa forum to find out about "natural swimming pools" (NSP's) in Thailand and the most recent post I found was from 2010, and even it didn't have much in the way of discussion.

Well, my wife and I bought a few rai of land on the outskirts of Bangkok and started building our own little homestead. The land had subsided substantially and was partially under water when we bought it, so I figured rather than fill it in with a bunch of soil, I would simply dig a pond out of the middle to fill in the sides. After reading up on NSP's, I fell in love with the idea of a naturally filtered swimming pond.

If you aren't familiar with the idea, there are a lot of beautiful pictures of these on the Internet. Here is a page with some of my favorites:

http://www.inspirationgreen.com/natural-pools-swimming-ponds.html

I think that the pond that I'm building is unusually large by NSP standards. It should end up being almost 2000 square meters. But I love water, and it seemed to make sense. :-)

(Our land is also connected to the canals of Thonburi, so I bought a long-tail boat which I really enjoy driving around the area, but that's another topic. And of course, the NSP is kept completely disconnected from the canal, except for overflow drainage.)

Once I decided to give it a try, I began doing my homework, and I've become quite surprised how well suited this area seems to be for NSP's. One of the biggest issues a lot of people discuss is how to line your pool to make sure the water doesn't leak out of the bottom. But after a few rains, it became clear that the soil on my land is naturally so high in clay that it is basically waterproof. When I dug down below the topsoil, I noticed that the pool of water left after a single heavy rain is still intact after several weeks without any noticable leakage. In fact, these rainwater pools remained so clear that they don't even look muddy. I've also tried kicking up sediment from the bottom, but it settles almost completely in only a few hours. A professional soil sample showed that it is basically clay down to a depth of about 20m. So I decided to give it a go without a liner. (I may regret this, but it sure seems easier!)

Additionally, many of the types of waterplants that are needed in the "filtration zone" of the pond are native to Thailand. In fact, I get a pretty good collection of water plants growing in every pool of rainwater after a few weeks without needing planting or tending. And since most of the literature is from European contries like Austria and Germany, much attention is given to how to handle freezing in the winter. (That's one problem we certainly don't have in Bangkok!)

So I'm wondering... has anyone encountered these in Thailand? I'm not finding much in the way of other people here building these. I hardly know what I'm doing since I've never built one of these before, so going to visit other examples would be quite helpful. Conversely, in case other people are interested, I decided to start a blog to explain the engineering and construction process (and the headaches I've encountered along the way):

http://mibproj.blogspot.com/search/label/Pond

But I'd be quite interested to find out if there are any communities of people building these in Thailand, or even what level of interest in NSP's there is here.

Does anyone know?

[xen]

Interesting project . I have worked in teams doing construction and maintenance of systems designed to purify street water run-off , mainly from the horticultural side of the projects . One thing there is quite a bit of research done in Australia on this and many of the water plants found in Thailand are also native to Australia . Often same genus but may be a different species .

I would also seek out some of the permaculture groups in Thailand who may have done similar projects. There are a few around Chiang Mai but they do tend to come and go.

[sappersrest]

great idea I know in the uk they use reeds, very interesting project, please keep us informed of progress

[mike324]

Please keep us updated, that is some good stuff. I've seem pictures of natural swimming pools and they look very nice. I'm guessing mosquitoes might be a problem here?

[NickJ]

Fish could eat the mozzies. I have just been concerned about the parasites in fresh water. There are a lot of them in SEA......

[IMHO]

Fish could eat the mozzies. I have just been concerned about the parasites in fresh water. There are a lot of them in SEA......

My little nephew tripped over and fell into a puddle on the street the other day - and got a swollen face from the nasty infection that followed. I'm not so sure I'd want to swim in a pool that didn't have chlorine sanitation.

[xye]

Please keep us updated, that is some good stuff. I've seem pictures of natural swimming pools and they look very nice. I'm guessing mosquitoes might be a problem here?

The hope is that with circulation pumps, the turnover rate should be enough that the mosquito larvae can't survive. Also, the circulation is towards the planted "regeneration zone" where dragon flies are supposed to come to prey on the mosquitoes. At least that is the theory. We'll have to see about the reality of it...

But since my land was underwater before I began, at least the circulation has got to be better than the pre-existing stagnant swamp in this regards. ;-)

[xye]

Fish could eat the mozzies. I have just been concerned about the parasites in fresh water. There are a lot of them in SEA......

The basic idea of "natural swimming ponds" (or "organic swimming pools" depending on who you talk to) is to circulate the water through a plant zone that also grows a layer of "good bacteria" (known as a "schmutzdecke") that basically outcompete all of the other organisms around. This includes algae and other undesirable microbes and parasites. In a way, rather than sanitizing the water with chlorine or some other chemical process, you are trying to starve the water of all of its nutrients so the undesirable organisms can't survive. (Such as algae, which I read are the main foodstuffs of mosquitoes.)

Unfortunately, fish food and fish poop are big nutrient sources for algae and other organisms to feed off of. So no fish in this pond. (Although due to the layout of my land, there is actually another unconnected water feature about 100m long, 4m wide, and about 2-3m deep that I am tempted to try raising fish in for food.)

But hopefully by starving the mosquito larvae of nutrients, water circulation, and any dragon flies that decide to try making a home of the plant zone, the mosquitoes won't be very successful. And maybe the other parasites too.

I'm planning on getting professional water testing done after the pond is built, so hopefully I'll find out if there are any baddies in the water before I go swimming. And as I mentioned in an earlier reply, the choice wasn't between NSP or dry land (or even between NSP and chlorine swimming pool given the size of the thing), it was between NSP and a giant stagnant swamp. So even if it isn't clean enough to swim in safely, it'll be a lot nicer and cleaner than the alternative.

As a side note, my wife and I are working on a design for a house floating in the pond. The house is actually designed to be a giant off-grid autonomous propeller driven robotic boat. (My wife is a roboticist, and we have a history of building various robots together. The biggest so far was an autonomous car, but this one will be a bit more ambitious.) While it is only meant to travel around in the pond on our land, the idea is to be able to move the house around the land as desired. Just imagine, orient the dining room so we can watch the sunrise while eating breakfast (on the rare occasion we wake up that early), and then reorient the house so that we can watch the sunset while eating dinner! Or move the house away from whichever neighbor happens to be making a lot of noise on a given day.

Having clear algae-free water in the pond should make the aesthetics of the "floating house" idea much nicer.

(And yes, we are a bit techie crazy. But yes, we are going to try to build it anyway. Please wish us luck!)

In case anyone is interested, I've attached an image of the floating house that I posted to my blog a while back. It is only a very rough CAD mockup, but it is a starting point for us.

Edited August 30, 2015 by xye

[sappersrest]

Absolutly a fantastic project, I am sure if you get the flow rates correct through the plant bed I am sure it will succeed,If it works well it will be one in the eye for old school pool engineers such as myself.

Good luck keep us posted.

[mike324]

Pretty cool what you and your wife does together! Sharing the same hobbies.

[Deelectro]

Very glad you started this thread. I plan to build one within a few years when the funds come through for one, (and oh yea, a house), so I hope there is more discussion coming on Natural Pools in Thailand. I did visit one at a unique hotel, the Mirabel run by a very nice French fellow just outside of Pattaya. The intel I got from him is that the challenge is keeping the water temp LOW enough to prevent algae and other undesirables. He had some underground tanks for that, and also pumping the water up to some waterfall features will probably help cool it as well. In this case the only ongoing cost will be electrical for pumps. Hopefully solar cells will improve to the point where it is not a factor.

I did read a comment in another pool thread that it wasn't possible to keep Natural Pools sterile enough, and they are getting banned in the west. Not sure if I believe that, and the one I saw was perfectly clean and clear.

Also the question of fish, they eat mosquito larvae, but also leave their droppings which could lead to growth of algae and or bacteria(?). Which way will the trade off balance out?

Any further input and personal pictures on building and Maintaining Natural Pools in Thailand would be greatly appreciated.

Edited July 28, 2016 by Deelectro

[charliebadenhop]

I am quite vague on the specifics, but since I have a similar interest, I read a long time ago that in certain parts of the world, their are organisms (was it snails?) that can bring serious infection into the water. Sorry to not be able to be more precise. Not sure where to point you for further info.

[charliebadenhop]

Here. I found this post from someone to me, a while ago...

Wiki says

The life cycles of Schistosoma japonicum and Schistosoma mansoni are very similar. In brief, eggs of the parasite are released in the feces and if they come in contact with water they hatch into free-swimming larva, called miracidia. The larva then has to infect a snail of the genus Oncomelania such as species of Oncomelania hupensis within one or two days. Inside the snail, the larva undergo asexual reproduction through a series of stages called sporocysts. After the asexual reproduction stage cercaria (another free-swimming larva) are generated in large quantities, which then leave (shed into the environment) the snail and must infect a suitable vertebrate host. Once the cercaria penetrates the skin of the host it loses its tail and becomes a schistosomule. The worms then migrate through the circulation ending at the mesenteric veins where they mate and start laying eggs. Each pair deposits around 1500 – 3500 eggs per day in the vessels of the intestinal wall. The eggs infiltrate through the tissues and are passed in the feces.

So... people pooping in rivers etc. can be a big factor.

Trying to imagine a possible chain here...
Snails would need to be infected in nearby water, and then the infected snail would need to make it into the swimming pool, yes?

Perhaps the first question then becomes- What is the likelihood of such parasites in the area I live in?

[Deelectro]

I think you mean Schistosomiasis, not sure why I remember it, but read about it years ago when travelling. However that is supposedly in stagnant unclean water that the snails get infected. A natural pool, if maintained correctly should be almost perfectly clean.

[charliebadenhop]

Again, I am just trying to get educated, and not looking to scare anyone.....

Here-

Schistosomiasis is a disease of poverty that leads to chronic ill-health. Infection is acquired when people come into contact with fresh water infested with the larval forms (cercariae) of parasitic blood flukes, known as schistosomes. The microscopic adult worms live in the veins draining the urinary tract and intestines. Most of the eggs they lay are trapped in the tissues and the body’s reaction to them can cause massive damage.

And-

Public health authorities report no new human cases of S. mekongi and await WHO evaluation and verification. Cases were previously reported in the region of Chong Mek (near the confluence of the Mun and Mekong rivers) in Ubon Ratchathani province on the border with Laos. Snail intermediate host: Neotricula aperta.

Read this thread

http://www.thaivisa.com/forum/topic/150224-bilharzia-water-born-disease-in-thailand/

So, I am thinking this should not be a problem in my area, which is Chiang Rai.

Anyone with further thoughts or knowledge?

cb

[Deelectro]

Moving along, lets say we've evaluated this already, now back to building considerations

 

[charliebadenhop]

Happy to hear more from you!

 

https://www.niftyhomestead.com/blog/natural-pools-swimming-ponds/

 

http://naturalhomes.org/naturalliving/organicpools.htm

 

http://www.organicpools.co.uk/

 

[JaseTheBass]

Moving along, lets say we've evaluated this already, now back to building considerations
 

Is the pool done yet?

Sent from my Cray II supercomputer

[RichCor]

Probably designing and building it at a snail's pace   

[John F]

Please keep updates coming as and when. I'm going to have a pool built in two years and would really like a natural one. Any information you can share will be priceless.


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