Mustard algae killed, now pool is cloudy(3 days) ???


New member
Sep 6, 2010
Hi All - So about a week ago I noticed what looked like "dirt" accumulating on the bottom of the pool. At the time we our pump and filter were in decline and we were tying to get someone out to repair/replace. By the time we realized the pump was just about gone (and old and undersized) the pool was starting to look swampy. We replaced the pump with a new slightly bigger unit(1HP from 3/4 hp) and got a sand filter better suited for the size of our pool (36x18).

On Friday evening I shocked with cholrine to above 20ppm then tried to maintain a high FC all saturday(never below 10-12). On Saturday evening and on Sunday morning I used a granular chlorine shock that had some algae killers and clarifiers. Since then I have just kept the FC level up. By Saturday morning the green color was gone and the pool actually had a nice shade of blue and was clean (I kept the pump and filter running 24/7 with side suction cleaner on for cleanup and circulation). Since then it has kept the blue color but has been dull and cloudy with no real improvement. I can barely see to the bottom on the shallow end. I have tried to remain patient and keep the pump/filter on (which BTW, my pump has randomly shut off about 4-5 time in the past 3 days running it 24/7 - is it getting overheated?) but the water doesn't seem to be turning.

Here are my current readings, done 5 min ago:
FC: 10.0 ppm
TA: 150
PH: 7.2
Calcum Hardness: 200
CYA: Not sure, I have not got the hang of reading this, it's either so low that it doesn't work or I have bad agents. The water to test never seems all that cloudy and I can't seem to get a good reading - or it's very low.

Should I keep the FC higher? Keep shocking? Raise PH? If everyone says to just wait and keep running 24/7 then I will but it seems like it should be turning slightly by now.



In The Industry
Jun 11, 2010
Vernon BC
Welcome to TFP!! You will be a pro by this time next year if you put the time to read in, i guarantee it!!

couple of questions.
Have you backwashed your filter and how many times if so?
What EXACTLY are you using to shock, please read the label and let us know.

I am not sure about your pump shutting off, but hopefully someone will chime in.

Please do yourself a favour and go to the homepage and read the article labeled "turn your green swamp into a sparkling oasis" or something to that effect.

Algae sucks bud, its alot of work. i would suggest you continue with keeping your chlorine level up but i have no idea what you are using, so please do tell us.


New member
Sep 6, 2010
Thanks! Yes, I am a newbie at all this; first pool, only been "learning" for about two months and determined to maintain the pool myself and keep it clear and trouble free if at all possible.

The shock I used was just something I found at Home Depot (Leslie's was closed). The ingredients are:

Trichloreo-s-triazinetrione 71.8%%
Boron Sodium Oxide 8%
OTHER: clarifiers, filtration enhancer, sun protector (no ingredients listed) 20.2%

That shock I used was the first time I had, I have been using just regular Clorox bleach to shock and raise FC but I did get some liquid chlorine 10% so I was not going through so much bleach with this recent algae episode.

Something else I forgot to add is it's still pretty warm here in Arizona and the water temp is around 87-88 degrees.

Also it's a vinyl lined pool - I am going to read that article now!!

I backwashed the filter about 4 times up until Sunday morning and haven't done anything since. It was running clear right away last time and I read somewhere that I should wait until it is completely full to backwash again.

Other Threads of Interest