I’d be grateful for some advice please. Our salt pool water has a slight tinge of green which I know is dangerous - it can go like pea soup so quickly. Also checking free chlorine it is virtually 0.
Normally we would add chlorine overnight but checking the pH just now it is over 8.
What do we do? Can we add more chlorine?
Thanks for the help.
Shouldn’t you add some eau de Javel first to drop the pH. IIRC edj is just a form of hydrochloric acid, so it should help get the pH down before you add the chlorine. @Corona
Yes, add some 9.6% (i think) chlorine EdJ, Do you know the calculation for your sized pool to get between 3 and 5 ppm (mg/litre)? I think its about 50ml/m3, I’m sure @Corona will be along soon though
I’d go for a higher dose overnight , good luck
Thanks Mark. I’ve gone back to this thread … I realise I keep coming back to this, sorry.
We’ll put in 5lts tonight. I thought that pushed up the pH even higher? Do we then bring the pH down? Or first go through the flocculent routine tomorrow and then do the pH later?
I’ve just looked up eau de javel - it’s bleach, and NOT hydrochloric acid. Wait for Corona to comment.
Sodium hypochlorite
Get the chlotine added and then worry about the pH. I always used to aim for a pH of about7.8 so it might not be too far off.
You can use javel (bleach) to shock and get the chlorine level up so it gets rid of the green tinge - start of algae. Once you have a reasonable chlorine ppm you could go back to your liquid or tabs (whichever you normally use.
Thanks everyone. I’ll let you know how it goes tomorrow.
Sorry Sue, been a really hectic day, leaving for the UK.
Yes get some EdJ from a brico shed and shock the pool. Put in about 10 ltrs for a quick kill of the algae and dont worry too much about pH as any additional rise will be due to the shock so will subside as the chlorine gets used up.
Could be your salt system isnt producing chlorine so check salt level and test the water right by the pool return inlet.
Thanks Corona - no need for apologies - hope trip back to UK goes /has gone easily.
We shocked the pool last night and it’s a reassuring blue today. Still a bit murky, over 8pH and no free chlorine (tested by inlet). OH has added salt tabs to the pool.
He has wondered whether the salt system isn’t producing chlorine. What are the implications please?
Implications are having no free chlorine😬. Not sure how you can test the salt chlorine generator though. Maybe get more EdJ and then some 200g chlorine galets, just to be on the safe side
Salt cells, the part with the plates have a finite life span. However they can also need a soak in dilute acid to descale them, scale builds up around the electrical connection ends leading to a short circuit and no chlorine production. Always worth a good soak and clean before going down the expensive replacement of the cell route. Test salt levels to make sure its in range, try to see if there are fine bubbles being produced in the cell, indicating some chlorine or hydrogen oxygen is being produced. If OH has a multimeter they could test for electrical output at the external connections of the cell.
Thanks Corona. This is embarrassing - we have never cleaned them. The guy who installed the system did not explain what we had to do.
It also explains a lot. Our pool always used to behave beautifully but has not done so in at least the last two years.
I have been looking at videos and now have a general idea what to do. Unfortunately our system - Dexton - I’ve not managed to find any instructions for getting at the salt cells. Their manual is pretty poor.
We’ve decided we have to wait until our current guests leave in just over a week so that we have time to sort this out in case anything goes wrong before the next lot arrive. So in the meantime we will do the best we can.
May I ask please? What would be your recommendation re the acid to use and its concentration?
If I may, I’ll post some photos of the system and ask for everyone’s views on how we proceed. Thanks.
Dexton is Cash Piscine’s branded products.
Depends what you have available in the house de scaler wise. I use hydrochloric acid diluted 4:1 and soak the cell for 15-20 minutes until it stops lifting off the calcaire. Plug one end of the cell with bung and pour it in the other end, leave to soak…
Should be in the plumbing line after the filter, if it was done well its on a loop to make servicing easier.
Not stepping on your experienced toes Corona, diluting hydrochloric acid could be hazardous if done incorrectly. I have always used vinegar to de scale my salt cell, probably not as quick but still effective and less risky ?
As I said, depends whats in the house for descaling 
I figure if people have hydrochloric in the house they are aware of the risks. Yes strong white vinegar is fine. Citric acid as used for coffee machines kettles etc
Its a good call Peter, so easy when you are doing this to make sure its explained to others not used to it.