Which pool

For anything to do with the garden and pool
mrmint
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Which pool

Post by mrmint »

Hi everyone
Just looking into buying a 5m x3.50 above ground pool (acier). what should we be looking for when buying, regarding the pump and filter etc. We are totally new to pools all advice is welcome.

Peter
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teapot
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Post by teapot »

Hello Peter,
If the budget would allow, then the pools with the timber surrounds are a lot better for several reasons. Above ground pools not having the benefit of the ground for some insulation are often cooler because any breeze will cool the water easier. Wood being a better insulator than aluminium can help. The wooden structure is self supporting making a good solid structure and adding decking it easy too.

The liner thickness in some pools is a 30 or 45/100 spec (thin) whereas the wooden ones are normally 75/100 much higher quality liner material so damage is less likely and longevity better.

Getting back to the filtration, the health of your pool depends on the filtration working well and with some above ground pools these are treated as the poor relative but the same issues affect them as they do in ground pools.

The filtration often boxed in with the above ground pools is generally under specified for the job so if possible buying you own separately is a better option or at least go up a size on filtration. It doesn't matter what the box says the filtration rate is they seldom if ever hit that figure as the physical size of both the filter and the pump just won't manage it and best to avoid at all cost small pleated cartridge filters, sand filters are better and easier to maintain.

A pool pump has to run for many hours and the electricity they use is quite a lot, for the size you are looking at probably 400w an hour for 10+ hours in summer. If you are interested the filtration can be altered to run Eco and that would reduce the electricity to around 50w per hour making big savings may alow you to afford a better pool.

These are on the assumption the pool is for your own use and not for gite guests as different more stringent rules apply.

I hope that is of some help, don't be afraid to ask for additional information.
Regards
John
Passivpool Energy "A" rated Swimming Pools, the most efficient, lowest running cost pools in the world
mrmint
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Post by mrmint »

Hi John
Thanks for all the info. The pool is for a gite, 4 people. The pool we are looking at comes with a sand filter and pump 3.5/hr.
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teapot
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Post by teapot »

Hi Peter,
For a private pool you can do pretty much what you want regarding water flow treatments etc. That is to say no ones bothered what you swim in but if your pool is for use by more than one family and that includes follow on families as it's possible to pass on infection from one to another, there are regulations to take notice of.

Now it is true you don't get an army of french Civil servants covering the 1000's of pools being used by Gite complexes, camp sites and Chambres d'hotes but they do exist and they can come knocking and some of the points are:

The turnover rate for the water should be 4 hours for pools over 1.5m deep and by the book 1.5 hours if less (which is quite ridiculous) they do go a bit easier for pools of less than 240m3.

There should be sufficient number of skimmers to clear the pool of debris and one skimmer per 25m3 of water. For your proposed pool at around 22m3 one should be fine.

If you use a sand filter the flow rate through the sand filter should be between 10-20m3h per metre of filter area for a good filtration
Disinfection must be by direct chlorine dosing and not by hand or from salt chlorine generation unless it's a bulk chlorine generator and then directly dosed.

The levels are 0.6 - 1.5 ppm if you are not using cyanuric acid stabiliser and 2.5-3.0 ppm if you are, with a maximum level of 60ppm for the cyanuric acid

Bromine likewise has to be dosed and between 1-2 ppm

Testing should be with DPD tablets via a comparator or photometer and pH via phenol red in the same equipment. Dip strips and OTO (yellow liquid 5 drops etc) are not allowed.

Chemicals should be locked away from access by guests and should have the relevant labels showing the hazard codes for each product.

There should be a 30litre per day per bather of fresh water into the pool and pools are supposed to be drained once a year for cleaning.

It is a pretty good bet that the 3 largest pool companies do not follow France's own rules and are still building pools that do not meet the specification in anyway.

If someone gets ill then inspectors will appear from everywhere and Cryptosporidium is one of the chlorine resistant bugs that is small enough to pass through a filter so requiring flocculation to remove it which again leaves out Desjoyaux, Magiline and Waterair as flocculation cannot be used on their setups.

Hopefully you can read between the lines of what I mean there.
The figure quoted for the sand filter setup on your proposed pool is a bit wishful thinking (3.5m3/h). The hoses supplied are of the convoluted type and these have horrendous flow characteristics compared to the normal smooth walled type either flexible or rigid and the filtration is really too small. The setup supplied would give a slow water turnover +6 hours and attempting to improve on that with the existing setup would be pointless.

Increasing the filter to a bigger size around 500mm dia would give you the best filtration and flow rate for the size of pool and allow you to run an Eco pump (low energy, high output) which will recoup your total spend on the pool within it's life span.

I hope I am not confusing the issue but I am trying to put over the difference in the French authorities eyes of a private/public pool.

Regards
John
Passivpool Energy "A" rated Swimming Pools, the most efficient, lowest running cost pools in the world
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bornintheuk
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Post by bornintheuk »

A number of gite owners (some of them LMHers) do advertise their properties as having a "salt water pool" as though its a benefit over standard chlorinated pool systems. Not only is this open to debate as the salt water generator turns salt in to a chlorine for disinfection but also, as teapot points out, they are not "advised" by the authorities.

One needs to be aware, just saying :wink:
What would Plato do ?
mrmint
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Post by mrmint »

Thanks John for all the info. I presume you have a pool business ? Website ?.
regards, peter
mrmint
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Post by mrmint »

Thanks bornintheuk
Not considering a salt pool , so thats one less thing to think about.
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