green pool water after vacuum

[ahvroom]

Merry XMAS, and please dont shoot me for not knowing all the values of the Ph, Clorine etc.

Situation is like this
my sister just moved to Spain and has a pool.
approx 5 x 8 mtr

the water was clear, but the whole bottom was covered in thick layer of algae.
I took the vacuum and used the pump to remove all the alga from the bottom

had to clean the filter many times and did good number of backwashes of the sand filter.

the bottom is now free of algae BUt, the water is now green.
probably from the movement of the vacuming.

what do: Just let it rest and the another vacuum??

please give me couple tips. Would be most appreciated

and the Ph (with a testing kit) look ok (light red)
but the clorine did not show in the test kit. So I added a tablet in the filter.

there is a witerizing container hanging there. It smells like a clorine bomb.


thanks
Alex

[Denniswiseman]

You really need a FAS/DPD test kit to be sure of your numbers
FC:
TC:
pH:
TA:
CH:
CYA:
You will also need to Slam (Shock Level and Maintain)
You say you added a tablet which I suspect is Trichlor or Dichlor. If this is your normal way of chlorinating then you probably have an excess of Cyanuric acid which renders your chlorine ineffective as indicated by your Chlorine / CYA Chart
For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm

[ahvroom]

Thank you for taking the time to answer

But. It is my sister’s pool. She took possession of her new house last week (incl the pool)

So. There is no known history.

I cleaned it to the extent of my capabilities (not much). And advised her to get a pool-expert to come and to get a maintenance contract.

Bests

Alex