Proper information on pools

Whilst James has been playing with the forum I gave up on it. Now it’s back to a usable format I have read some of the posts that appeared whilst I was away. I posted some information on the first version of SFN which many seemed to have overlooked now and there have been lots of posts that are complete nonsense on how to look after and treat your pools. This especially applies to when you have let them go green.

  1. Chlorine is the best anti algae, it works faster and better than most other things.
  2. Packaged tablets of chlorine (choc, multi action and Lent) are nearly always stabilised chlorine so the more you add the higher the stabiliser level goes.
  3. Stabiliser AKA Cyanuric acid is more in control of your pool water than the pH is, people check the pH levels but don’t check the stabiliser level. Most green and problematic pools are down to too higher level of stabiliser and you cant accurately check stabiliser with dip strips.
  4. Anti algae unless it’s copper based doesn’t actually work if you have a green pool already, it’s an industry con! More of your valuable chlorine is used up burning the anti algae out of the pool so making the situation worse!
  5. Hydrogen peroxide is a waste of money as it is a stronger oxidiser than chlorine (but a worse sanitiser) it burns out the chlorine in your pool so you cant get a chlorine reading until it’s gone. It cost twice as much as chlorine so why not buy twice as much chlorine and look after your pool properly?
  6. You can look after your pool very easily and cheaply just using Eau de javel (for a source of liquid chlorine) and acid (pH-) from a Brico store. If you need to increase the alkalinity (for a tiled or plaster finished pool) bicarbonate of soda from the super market, Most vinyl liner pools the alkalinity doesn’t matter unless you have a specific problem like pH drifting so ask for specific information.
  7. choc’ng a pool is NOT about buying a product called choc, it’s about raising the free chlorine to a level where everything is oxidised out of the water (algae, chloramines etc) and you may need to hold this high level of chlorine for a few days. A one off dose of chlor choc pastilles is not going to achieve very much except raise the stabiliser level some more.
  8. Stabiliser level once it gets too high needs to be brought down by emptying some water and replacing with fresh.
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I live in the Luberon and have used an automatic system for 3 years now and I can recommend it. Using an internet connection the health of the pool is monitored remotely and checked every day. If it needs attention a service man will come that day. The parameters checked are quite comprehensive and the system ensures a clean and healthy pool. If anyone is interested I can send you the link.

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Yes Roger, there are many systems around and the list is growing. Every time I attend a commercial show there are more and it does make things easier. Its probably why salt systems catch on as its usually the first time any form of automation is involved. Its still very important to manually test as probes need recalibration from time to time and some need frequent replacement. This is a long way from adding a tablet to a flying saucer and hoping for the best.

Merci John for your concise counsel. I like your flying saucer imagery.
I seem to recall that you can correct pH + with HCl - works for me.
Is there a link to the original article you wrote a long time ago? I found that quite useful.
Any recommendations on painting products for renewing cement pools?
Thanks again.

Yo John, nice to have you back.

I always listen to your advice which is sound and sensible, although I don’t always follow it.

Yes Willa the original article is around somewhere as James asked me to take backup just before the forum changed. I will look it out, maybe up date it a little and post it back on here.

There are several coating available for concrete. Painting with a specialist epoxy pool paint is a good one but I would steer well clear of others like chlorinated rubber paints or similar. There are several spray on coatings that have to be applied by contractors mainly because of the cost of the equipment. These range from polyurea coatings that make a tough liner type coating or an interesting finish looking like a coloured stone effect, known as aquaBright.

Tony, I am still writing my book on pools and trying to make it an interesting read is the hardest part, sound and sensible could have you asleep in minutes! Edgy and controversial makes it interesting so you follow what you need to.

HI John,

Interesting article, and I found it really helpful.

My only question is regarding the Stabiliser Level. How do you alter this?

Hi John,
Stabiliser or Cyanuric acid (acide de cyanurique) can be purchased as a granulated product in tubs much like any other pool chemical or sometimes as a liquid. The granules take a long time to dissolve 1 week plus, so should be put into a floating dispenser or a stocking near a water flow (inlet or outlet) As the name suggests its an acid so don’t allow it to rest on a pool surface etc. Most packaged products contain it Choc, lent, multi action galetts. The cheaper versions of the multi action etc usually contain less chlorine and more cyanuric acid (CYA). the info is on the back of the packaging.
Trychlorinated isocyanuric (3 parts chlorine 1 part CYA) Dichlorinated isocyanuric acid (the cheap ones 2 parts chlorine 2 parts CYA) or thereabouts.

Once you have a level of around 30-50ppm you don’t really want any more so if the pool uses packaged products for a couple or more seasons it is quite likely the level has risen. There are occasions over winter where the CYA level can drop to zero due to a bacteria that tends to convert it into an ammonia based compound which can be a devil to shift come the start of the new season. Other wise it really means draining and replacing some of the water with fresh. I have on occasion managed to lower the CYA by oxidising it out with a lot of chlorinating liquid (unstabilised) because we couldn’t empty the pool. It takes a lot of chlorine to do this and a few weeks but it can be done.

Unfortunately Dip strips cannot accurately measure this chemical, you will get a colour change but it unlikely to be accurate in any way. I have tested pools with 190-200ppm of stabiliser and the dip strips showed 30-50ppm.

Hope that answers your question.

Hi @John_Withall can you offer some advice on how to correctly shut down swimming pools for the winter, what options we have please?

Good to hear you back John! Since ‘listening’ and following your advice on pool care, my pool (A desjoyeaux!) has been a whole lot easier to maintain. Especially controlling the stabiliser level to avoid the chlorine ‘locking up’ and not clearing the algae. If everybody just followed your 1 - 8 above their problems would be minimised. Although your alternative means to lower CYA are valid I’m sure, I will just follow plan A (above) and not complicate my mind with alternatives. Thanks, as ever.

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Hi John,
Thanks for this. How do you know if you have too much or too little ‘stabiliser’? What is the best method to test for this, and measure this? I have used a multi-purpose test strip (Ph, free chlorine, Total alkalinity & stabiliser) but am not confident with the readings. It’s all new to me.

Hi John, hope you’re well?
Having established a much improved management process for my Desjoyeaux pool over the past few years (especially in relation to controlling CYA levels), mainly thanks to advice gleaned from your goodself I found last year that algae needed constant attention to keep the pool clear.
This may have been the weather or perhaps the recirculation pump has ‘slowed’ down after 18 years service?
Either way and knowing that Dessy pools need a lot more attention than traditional set ups, I am considering a conversion to the sand, skimmer and pumphouse set up.
It is a10mtr X 5mtr pool’
I’m not really considering a DIY job, but wondered if you have any knowledge or indeed advice on the feasibility of the conversion and roughly how much it would cost?
Cheers
Paul