Another cloudy thread✌️

Mopar4u

Well-known member
May 24, 2021
48
Wisconsin
Pool Size
7000
Surface
Vinyl
Chlorine
Liquid Chlorine
Intex above ground 7000 gallon pool in wisconsin. Learned from this site how to maintain my pool 3 years ago and have truly been trouble free til this week. I use 12.5% liquid chlorine for sanitizer. I use intex’s largest sand filter. Backflush and rinse every sunday. Filter runs 12.5 hours evening til dawn. I have the intex zx300 “auto” pool cleaner always attached so it cleans when the filter is on and cleaned every sunday. Taylor k-2006 test kit with fresh reagents to test FC PH and CYA (thats all ive maintained over the years).

Early this week i noticed the water was cloudy. Coincidence or not, it was on the same day we got nasty air quality from the canada fires. I switched the filter to 24 hours on. No change the next evening. I reslized that i think i was testing FC using the 25 mark but dividing by 0.5, oops. I went into slam mode.

First evening slam
Cya 60
CC 0.5
PH 7.4
FC added to get 24 in evening per pool math app. Checked FC 2 hours later literally no change. Checked next morning (about 12 hours since start), FC is 23.4. PH was off the chart high i believe. Checked at lunch today (sunny today) FC 22.

Filter and cleaner are still on 24 hours. Do i just need to stay patient and continue to monitor FC?





IMG_6122.jpeg
 
Backflush and rinse every sunday
That's an awful lot of backflushing. Is your pressure rising 25% in a week? I can go all season with only backflushing a couple times.
PH was off the chart high i believe.
pH tests are invalid when FC >10 ppm. That's why once you start SLAM, you ONLY TEST FC and CC.
Do i just need to stay patient and continue to monitor FC?
Yes. POP. (Pool Owner Patience). There are THREE criteria to completing a SLAM. You have only completed two of them. Assuming A) you tested your night time at least 30 minutes AFTER adding your last chemicals for the day AND it was after sundown and B) you tested FC for the first time the next day before sunrise.
 
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Welcome BACK Mopar !!!

PH is invalid at 10+ FC, usually reading a false high like you saw.

Switch to 10ml samples and each drop is .5FC. You'll save 2.5x the supplies. Heck. Until you need closer accuracy, use 5ml and 1 FC per drop. For now, POP and maintain the 24.

Do you still have the 2nd filter rig ?
 
Thank you for the detailed response.

No pressure rise. I backflush every sunday just to keep things tidy, is too often bad?

Noted on ph tests.

Your A and B assumptions are accurate.

Is there anything else i should be testing for or doing besides filter on 24 hours and keep fc at slam level til water is clear and continues to pass oclt? Shouldnt the FC dropped overnight if there was an algae issue? Patience arent a strength of mine🤪
 
Welcome BACK Mopar !!!

PH is invalid at 10+ FC, usually reading a false high like you saw.

Switch to 10ml samples and each drop is .5FC. You'll save 2.5x the supplies. Heck. Until you need closer accuracy, use 5ml and 1 FC per drop. For now, POP and maintain the 24.

Do you still have the 2nd filter rig ?
I actually have a 2nd and 3rd…. In case #1 fails. I have a smaller sand and the cartridge that came with the pool.
 
Is there anything else i should be testing
FC only for now. When the water is clear, add OCLTs and test CCs too. Vac and brush as often as you can muster.
Shouldnt the FC dropped overnight if there was an algae issue?
It may all be dead in the water, but brushing could expose new wall/floor algae that needs killing.

Or it's ash from the fires.

Either way, if the FC is holding, it's a gift. Do not question it and risk angering the pool gods.
 
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No pressure rise. I backflush every sunday just to keep things tidy, is too often bad?
@Newdude beat me to the other answers, but I'll stab at this one. There isn't a need. I have found a slightly dirty filter actually filters better. I can't quote something from the wiki here, just my own impression. Then you also have the lost chemicals to deal with.
 
I have found a slightly dirty filter actually filters better. I can't quote something from the wiki here,
The crud trapped in the filter, filters finer crud. So a dirty filter is more efficient than a clean one, to a point when it noticeably reduces flow.

Carts and DE start at finer filtration and sand filters take a bit to catch up.
 
The crud trapped in the filter, filters finer crud. So a dirty filter is more efficient than a clean one, to a point when it noticeably reduces flow.
Woohoo! Non-scientific Daniel wins a battle! Now to only put this in the wiki somewhere. LOL. (Yeah, I don't think it belongs anywhere other than in our minds).
 

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It actually is mentioned in the wiki ;)

A slightly dirty sand filter works better at capturing and filtering stuff. Only backwash when your filter pressure raises 25% over your baseline clean pressure.

Well I'll be danged... I shall now go back to my hole eating popcorn and watching threads. LOL! I cannot believe i missed that in my google fu searching.
 
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