Extremely cloudy water

[paokaras31]

Hello everyone!
My pool was extremely clear and well balanced until 5 days ago...
we had a problem with city water. We had no water for 2 whole days. During those 2 days we continued using the pool with no problem. (By the way the pool is inground plaster/tiles, 80000liters with an overflow canal and reservoir which receives extra water from the city with a floating switch, sand filter to which I add DE, SWG, pH regulator .I have a tft test kit and use it regularly and I have my SWG figured out so as to measure FC once every 2-3 days. Never had problems ever since I discovered this site) The water came back on day 3. The same afternoon the pool started to get a little cloudy. I immediately ran a fool test which was as follows:
FC 7.5
TC 7.5
CC 0
CYA 70-75 (cant really tell where exactly the black dot disappears)
CH 350
TA 90
pH 7,6
Borate aprox 40
salt 3200
temp 27 celcius.

I started running the pump 24/7 and boosted the SWG since I had 0 CC.
The following morning the pool was a light brown mess I could not see 3 inches down
tests:
FC 12
TC 12
CC 0
the rest same as above

I backwashed the filter since pressure has risen 30% above normal and added DE as usual. Still ran 24/7.
The same afternoon the pool was worse than ever: extemely cloudy no visibility at all, color light brown
FC 10 TC 10 CC 0 (SWG at 4/10) pH 7.6
The overflow resevoir (which was half way empty during the no city water period) was even worse, very dirty. The city water is extremely dirty too. If you fill a glass from the tap you get a white cloudy thing and when it rans you can see the dirt in the bottom of the sink accumulating. (people in the village we live say the same and the mayor got sued allready).

I decided to flocc it and see what happens.... Does anybody have a better idea?
Thank you

 

[chem geek]

Not sure whether it's iron or just dirty particles, bu you can see if you can remove it by filtering and doing what you've been doing adding DE to the sand filter. You will probably continue to have dirty water so long as the city water remains dirty. Floc'ing might drop the current particles, but it won't stop new ones coming in. Let us know what happens -- clarifiers and flocculants do not always work well and some brands work much better than others.

 

[paokaras31]

Thanks for the reply! I stopped the overflow operation and now just filter 24/7 pool water only. 24 hours later and very little improvement, I decided to flocc. I will wait till tomorrow to see the results . The dirt particles are very small since they pass through my houses 50μm pore water filter.....

 

[chem geek]

If they pass through your 50 micron filter, then they will likely pass through your sand filter. You probably don't have these products, but the clarifiers we recommend for a last resort are GLB Clear Blue and BioGuard Polysheen Blue while for a flocculant it's OMNI Liquid Floc Plus.

 

[paokaras31]

Update. 48 hours after running the pump 24/7 no improvement. Filter pressure doesn't even rise!! I used an aluminum? based flocculant from the local poolstore. 1,5 litters in a 10lt bucket, spreaded over the perimeter, run on recirculation for 3 hours, shutt off pump. Now 24 hours later water crystal clear and bottom full of dirt. Will vacuum to waste this afternoon and uldate. Thanks for the reply Richard!!

 

[chem geek]

I'm glad the alum floc worked for you. Flocculation only works if you can vacuum to waste, but with a sand filter you normally have a valve to do that (like you did). For cartridge filters, most don't have that ability so in those cases a clarifier would be more helpful.

 

[paokaras31]

Update...
Everything is perfect today. We are going for a swim right now I emptied the dirty overfow tank (7000lt) and vacuumed its bottom to waste as well. Added salt and cya to it using the pool calculator after I filled it again (city water cleared up). I will add a little calcium chloride next week. It think I will flocc more often, now that I see how effective and easy it is, since I anyway get a lot of fine dust debree here and have to run the pump more than I have to....
Thanks for the help Richard. The more I read you in this forum the more I am amazed at your scientific basis and detail of analysis. You are the man!!

 

[paokaras31]

Update 2
Today everything looks fine. Had to do a lot of vacuuming to waste the last couple of days to get rid of the floccs in the bottom. I also emptied, cleaned, vacuumed and refilled the overflow reservoir. I estimate a total of 12000-13000 liters refill. Water crystal clear. So I ran a full set of tests this morning :
FC 6
CC 0
TA 220!!!!
CH 370
CYA 60
BORATES 20
SALT 2800
pH 7.3 (I have an auto ph regulator which feeds HCl)

Question :is it possible for my TA (which I spent 2 months last season bringing down) to have drifted this high just from refill water (I tested tap water and has TA 270)
Anyway I have set the pH regulator to 7.2 and started all over with TA. After correcting it last year I used up a total of 12 liters of liquid HCl all this season (including all of the off season from October to May) with pH set at 7.7 (I used 45 liters in two months to bring it down last season when I first filled up the pool) . Guess the dirty city water is going to cost me in Hcl as well....

 

[Abigail K]

Yes, it is possible, especially with the amount of water you replaced.