DIY small concrete pool

[Pichit small pool]

Hello every one.

First of all, thank you for this great forum, I found plenty of infos, advices, and ideas from the threads. A DIY pool looks very doable from what I have seen, but I still have doubts about a few things.

I plan to build a (very) small concrete pool, 4m long, 2m large, 1,2m deep, with an infinity edge on one 2m size wall. The water will flow in a 1 cubic meter surge tank, looking like "faranginkorat" did, which can be seen in this topic: http://www.coolthaihouse.com/forum/viewtopic.php?f=19&t=5077. It looks nice, and easy to build. One bottom center main drain, one water eyeball inlet opposite to the overflow edge, tiles for finishing, and sandwash for the deck.
I want to keep it simple and cheap, but strong and durable, without to much maintenance in the future. Budget, more or less 100k THB, hopefully.

Now, my questions:

- 15cm concrete floor and wall ,with one 12mm layer rebar. Is that enough ? Too much ? Or 20cm concrete ? Or two layer rebar ? Does the concrete need waterproofing, or only the render ? Possible to go without vibrating the concrete ?
- For the formwork, I don't want to rent steel, or to buy wood, so I think about a double blockwork. Is that fine or not ?
- The land is an old rice field with 1m top up soil. The bottom of the pool will be almost at the rice level. First rice field is 10m from my pool location. Do I need an hydrostatic valve ? Or a drainage pit ? Or both ?
- For the pump and filter, I found this: Emaux FSF350-SS 14" 0.33HP pump+filter combo, with zelbrite. Is that ok for this size pool ? Is Emaux reliable ?
- Is the surge tank big enough ? 1m3 for a 10m3 pool ? It is 10% as I have seen adviced, but because of the small pool size, the tank is pretty small.
- I want to go for a salt chlorinator, but I am a bit clueless about it. The smaller unit fit for about 40m3 pool, which is way bigger than mine. does it matter ? Is there smaller unit ? Any big difference between Zodiac TRi compact, and Emaux SSC15 except the price? There is also the Emaux SSC15 without timer. Do I need the timer ? (It might be obvious, but not yet to me !)
- About the tiles, can a local worker (working with traditional house tiles) provided with the right adhesive do the job, or does it take special knowledge ? Is it possible and worth to hire workers from the tiles compagny ?

That is all for now ! I am still planning, so I could use any suggestion or advice in case there is anything wrong.

Thank's a lot for your time and reply.
I can keep this post going on with pictures during the building if some are interested.

Regards, Pierre.

[Klondyke]

I want to keep it simple and cheap, but strong and durable, without to much maintenance in the future. Budget, more or less 100k THB, hopefully.

You can find some of my experience and pictures of an easy building style in my thread viewtopic.php?f=19&t=4736 . You can do it all far under 100k, if material and workmanship carefully selected and daily supervised.

here to your questions as per my pool (withstood 2 earthquakes):

- 15cm concrete floor and wall ,with one 12mm layer rebar. Is that enough ? Too much ? Or 20cm concrete ? Or two layer rebar ? Does the concrete need waterproofing, or only the render ? Possible to go without vibrating the concrete ?

Floor by mesh 20x20cm, 3mm wire, 10 - 12 cm concrete layer, cheapest foundation with CPAC, tiles with normal cement with addition of water proof emulsion. Pouring the concrete few days after backhoe excavation.

- For the formwork, I don't want to rent steel, or to buy wood, so I think about a double blockwork. Is that fine or not ?

Walls double cinder blocks, bonded by normal cement, under each 2nd layer to lay 3 mm wire, earth backfill behind the walls in portions whenever 2 - 3 layers are hard enough (after 3- 4 days)

- The land is an old rice field with 1m top up soil. The bottom of the pool will be almost at the rice level. First rice field is 10m from my pool location. Do I need an hydrostatic valve ? Or a drainage pit ? Or both ?

? Depends how high the ground water level reaches. However, once it is made during dry season, then after finishing to keep the pool always full of water. Perhaps a stronger reinforcement in the bottom will make it more secure.

- For the pump and filter, I found this: Emaux FSF350-SS 14" 0.33HP pump+filter combo, with zelbrite. Is that ok for this size pool ? Is Emaux reliable ?

Do not know that. But for that size you should not get headache with any pump. My pump for 60m3, 1.1kW was 7,500 Baht at pump specialist (not a pool specialist, there you will pay 3 x more). Look in GH.

- Is the surge tank big enough ? 1m3 for a 10m3 pool ? It is 10% as I have seen adviced, but because of the small pool size, the tank is pretty small.

Far enough, not depending on the volume but on the pool surface. Important to have a natural outlet, getting a lot of water from the pool when downpour

- I want to go for a salt chlorinator, but I am a bit clueless about it. The smaller unit fit for about 40m3 pool, which is way bigger than mine. does it matter ? Is there smaller unit ? Any big difference between Zodiac TRi compact, and Emaux SSC15 except the price? There is also the Emaux SSC15 without timer. Do I need the timer ? (It might be obvious, but not yet to me !)

I use copper sulphate for algae fighting, then a bit chlorine to be assured about bacteria growth. Not more germs in your pool than you get in Big C when shopping. A simple 24 h timer is OK for selecting the pumping time 5 - 7 hours daily.

- About the tiles, can a local worker (working with traditional house tiles) provided with the right adhesive do the job, or does it take special knowledge ? Is it possible and worth to hire workers from the tiles compagny

?
Any village bricklayer (chaang pun) should do it by a normal cement with addition of water proof. I prefer large tiles, if possible without grouting the gaps (there are some with very exact edges 60 x 60cm). The fashionable small mosaic tiles are very prone to a water with low pH, most of them are re-tiled within 7 - 10 years. A pH around 8 does not make any harm to the pool and to the human either. It's just a good income for the pool shops when following all their exact advices.

[olavhome]

Finished my pool a couple of months ago and used for about 1 month.
About surge tank, better have big than small.
When jump into pool 3 or 4 kids a lot of salt water go away and you have to use fresh water and add salt later to compensate if surge tank to small....
Also have the emaux clorinator With the timer.
Easy, starts and stop by itself, but of course you can also put a timer directly in the sockett.

[Klondyke]

Finished my pool a couple of months ago and used for about 1 month.
About surge tank, better have big than small.
When jump into pool 3 or 4 kids a lot of salt water go away and you have to use fresh water and add salt later to compensate if surge tank to small....

How many times you will get such a case: 3-4 kids in one jump? And how many salt water gone away? Surely, very special case within 1 month using.

Perhaps for the OF you do not have a "sloped smooth surface" that will return a portion of the water at every wave. (I have a 40 cm wide tile, sloped 1 cm inwards.)

And perhaps you keep the water level in the tank quite high. What for? When you get a rain downpour (as this is the case now daily) where the water (coming with rain) goes? (I suppose you do not have the pool with roofing.)

So, with a rain 5 cm (I got yesterday night, mostly is even 10cm) you will get some 100 cm more level in your tank within 1 hour, i.e. 20- 30 times more - in the ratio of the two water areas (pool:tank). (Then you can forget a wave from 3 - 4 kids.)

Anyway, after my 11 years I have another observing. (And with no saltwater to be worried about.) That's my advice for a reasonable investment.

However, it is up to the owner's thinkingover what's to provide for what case - for a pool 10 m3 ?

[Pichit small pool]

Hello Klondyke,

I had checked your thread already. Very interesting, and way cheaper than the average typical pool building, with great results. I am thinking of a mix between your construction, and a traditional one. Because of my lack of experience, I would feel better with something strong, even If It is a bit too much. Better than not enough ! But I have got plenty of idea from your pool. I like your home made water heater !

under each 2nd layer to lay 3 mm wire

Does it really help ? I have never seen this way around here. It look likes it is good to poor all at once, instead of multiple layer. Could that make the form wall strong enough to do it ? (with earth outside, and eucalyptus inside)

I use copper sulfate for algae fighting, then a bit chlorine to be assured about bacteria growth.

I like the way it feel with salt water, but the chlorinators are expensive. It is a very interesting way you are doing, and I might give it a try. Otherwise, there is almost always too much chlorine, and it make the swim unpleasant to my opinion. The chlorinator would be by far my biggest expense, like 1/4 of my budget ! Not decided yet.

Any village bricklayer (chaang pun) should do it by a normal cement with addition of water proof. I prefer large tiles, if possible without grouting the gaps (there are some with very exact edges 60 x 60cm). The fashionable small mosaic tiles are very prone to a water with low pH, most of them are re-tiled within 7 - 10 years. A pH around 8 does not make any harm to the pool and to the human either. It's just a good income for the pool shops when following all their exact advices.

Ok, thanks for the advice. Just, i do not understand how it is possible to tile without grouting ? It seems to me like even with a good job, it will always be some small leaks in between, no ? Or the waterproof render do the job, and the tile come over only to decorate ?


Hello Olavhome, Good to hear your pool is over. I didn't find any topic, did you made one ?

About surge tank, better have big than small.
When jump into pool 3 or 4 kids a lot of salt water go away and you have to use fresh water and add salt later to compensate if surge tank to small....
Also have the emaux clorinator With the timer.
Easy, starts and stop by itself, but of course you can also put a timer directly in the sockett.

I can make the surge tank bigger without trouble. 1m3 respect the 10% size advised by most, but my though is that if 4/5 persons swim at the same time, it is a huge volume to handle compare to a 10m3 size surge tank from a bigger pool for example. Don't know if I am clear... Is there only the size pool volume to consider when designing the surge tank, or is there any other factors ? Like a ratio surge tank/number of people in the pool ?

There isn't much difference between the chlorinator with or without timer (maybe about 2000THB). Can the chlorinator work with the same timer than the filtration ? Or is it an independent unit working separately ? In that case, it must be on a by pass, right ? Still have some search to do I believe !
Thank you for your time.

[Pichit small pool]

How many times you will get such a case: 3-4 kids in one jump? And how many salt water gone away? Surely, very special case within 1 month using.

Perhaps for the OF you do not have a "sloped smooth surface" that will return a portion of the water at every wave. (I have a 40 cm wide tile, sloped 1 cm inwards.)

And perhaps you keep the water level in the tank quite high. What for? When you get a rain downpour (as this is the case now daily) where the water (coming with rain) goes? (I suppose you do not have the pool with roofing.)

So, with a rain 5 cm (I got yesterday night, mostly is even 10cm) you will get some 100 cm more level in your tank within 1 hour, i.e. 20- 30 times more - in the ratio of the two water areas (pool:tank). (Then you can forget a wave from 3 - 4 kids.)

You've got rain ! Lucky you, I am still waiting here...
Some more infos to think about. Just preparing to dig, so still plenty of time to change anything.

for a pool 10 m3

Maybe I should call it a big bath instead ! But with two young kids, I do believe it worth it, plus I could enjoy it as well ! The small size will make it very easy and fast to maintain and keep clean. And of course, I can afford it !!!

[Breizh29]

Hi,

10% of the basin's water volume is generally considered to be a good solution for the buffer tank. If it's bigger it's not a problem but it's more expensive.

[Klondyke]

Hello Klondyke,
I had checked your thread already. Very interesting, and way cheaper than the average typical pool building, with great results. I am thinking of a mix between your construction, and a traditional one. Because of my lack of experience, I would feel better with something strong, even If It is a bit too much. Better than not enough ! But I have got plenty of idea from your pool. I like your home made water heater !

The complete pool 12x3m as you see in my thread will not cost you more than 150,000 Baht - once the material properly selected by you and the workers working as you want (not they want) and daily supervised.

under each 2nd layer to lay 3 mm wire

Showing picture of fish tank and my others storage tanks with double red bricks - without the wire reinforcement - and those without the earth backfilling as the pool get - all survived over 12 years with 2 earthquakes running water over.

I use copper sulfate for algae fighting, then a bit chlorine to be assured about bacteria growth.

but the chlorinators are expensive.

No Chlorinator, just within 2 -3 days a spoon of chlorine half dissolved in small (abnaam) bucket and distributed on the water area.

I prefer large tiles, if possible without grouting the gaps (there are some with very exact edges 60 x 60cm).

Ok, thanks for the advice. Just, i do not understand how it is possible to tile without grouting ?

The exact tiles (look like granite) fit together with less than 1 mm gap. The water will be held by the waterproof layer under the tiles. Not by the usual grouting 3 mm that will be eaten away by the pH 7.4 water (and strong chlorination) within few years anyway. And the gaps like to keep the algae and all the dirt that is difficult to clean.

[Klondyke]

Just to make clear:
All the kind advices of the pool shop experts about the chlorination: They advise for our MickeyMouse pools the same levels as for a public pool where hundreds of people with their pissing kids come. And they modestly forget to mention that for our own purpose that are quite different conditions, aren't they?

And for the strong chlorination, and if it should also serve as an algae fighter (what is not correct - for that other cheaper and more effective means are), the pH level is to be maintained what is also quite costly. Otherwise the pH is not harmful when is higher, like in the sea water and all spa, more than 8.

For example, the German government water standard for drinking water allows pH between 6.5 - 9.5. And for our swimming it is not so good?



For clarity of the pool water the pH value does not play any role. Everybody can test for himself.

BTW, the chlorinated water is not really very healthful, is it? Especially for small kids and people prone to asthma. Try to google swimming pool, chlorine water, cancer. (I think, the doctors who find it, do not want to sell anything, do they?) What we get during the day outside of the swimming pool is much more contaminated by germs, bacterias...

[Pichit small pool]

Thank you a lot Klondyke for all the valuable informations.

I think the building and equipment will cost me about 70k THB. Maybe a bit less, but I would rather spend less than I planned, and not the way arround !

Then, for the cleaning system, I still have to decide between your low level chlorine with addition of copper sulphate, or a salt chlorinator...