Another Green and now Blue

[Simon]

Got to the Pool Friday for a mid-summer check and it was green in spite of the pool-man supposing to have checked it.

So in goes loads of Javel and, pretty quickly it's back to blue, but a cloudy, turbid blue. After 24hrs (pump on all night) I had to leave, but it was still blue but cloudy (I did 2 backwash cycles during this period). Normally the pool is sparkling - so what's the problem? Is it just the dead Algae which need to break down and it's just a matter of time, or is there something else. pH was around 7.4/7.5 when measured after the Javel was added.

Thanks

[Théière]

First problem is your pool man.

Second although you have killed the algae, in doing so you may have used up the available chlorine so the shock treatment needs to be repeated until the chlorine loss overnight is less than 0.5ppm then you can stop shocking.  Time will help and who knows it may have cleared a day or two later, can you trust your pool man to check it. With the Ph around 7.4 after the javel had been added I would estimate your Ph is too low roughly 6.8 normally. this will help with the chlorine sanitation process but could cause skin and eye irritation.

All this is a little bit guesswork as we don't know the size of your pool and how much chlorine you have added and what the other levels are in the water and how you normally dose with chlorine.