Why does my pool keep going cloudy after heavy use?
- Thread starter syedsam
- Start date
William Walker
Member
I’ve had the same issue after pool parties too, the water gets cloudy after a lot of people swim, especially if they’re wearing sunscreen or body oils. I always shock the pool after everyone leaves, and the water clears up by the next day. Lately, I’ve also been checking the pH and alkalinity, since those can be affected after heavy use. Do you guys use any other tricks to clear up the water faster?
Michael Young
Member
I've had that happen too after pool parties! The sunscreen and oils can definitely cause the cloudiness. I've been checking the pH and alkalinity after heavy use to help clear it up faster. Maybe give that a try along with the usual shock treatment!
Mason Blake
Member
Yeah, that’s actually pretty normal after heavy swimmer load, but it doesn’t mean you just have to live with it.
When a lot of people swim, they add more than you realize to the water, sunscreen, body oils, sweat, deodorant, even detergent residue from swimsuits. Chlorine has to work overtime to oxidise all of that, and until it does, the water can look dull or cloudy even if it’s still “safe.”
A few things that usually cause the repeat cycle you’re seeing:
• Chlorine demand spikes after big swim days, so levels drop faster overnight
• pH often creeps up, which makes chlorine less effective
• Fine particles stay suspended until the filter catches up
Shocking fixes it because you’re basically resetting the water, but you can reduce how often it happens.
What’s helped me:
– Test and adjust pH before shocking (aim for ~7.4–7.6)
– Run the filter longer than usual after heavy use, not just overnight
– Brush the pool walls and floor so oils don’t cling and re-cloud the water
– If parties are frequent, a small dose of enzyme treatment helps break down oils before they become a problem
Also, quick win: have everyone rinse off before swimming. Sounds minor, but it makes a noticeable difference.
So yes, it’s normal with lots of swimmers, but if it’s happening every single time, it’s usually a sign the pool just needs a bit more post-party circulation and balance, not just shock alone.
When a lot of people swim, they add more than you realize to the water, sunscreen, body oils, sweat, deodorant, even detergent residue from swimsuits. Chlorine has to work overtime to oxidise all of that, and until it does, the water can look dull or cloudy even if it’s still “safe.”
A few things that usually cause the repeat cycle you’re seeing:
• Chlorine demand spikes after big swim days, so levels drop faster overnight
• pH often creeps up, which makes chlorine less effective
• Fine particles stay suspended until the filter catches up
Shocking fixes it because you’re basically resetting the water, but you can reduce how often it happens.
What’s helped me:
– Test and adjust pH before shocking (aim for ~7.4–7.6)
– Run the filter longer than usual after heavy use, not just overnight
– Brush the pool walls and floor so oils don’t cling and re-cloud the water
– If parties are frequent, a small dose of enzyme treatment helps break down oils before they become a problem
Also, quick win: have everyone rinse off before swimming. Sounds minor, but it makes a noticeable difference.
So yes, it’s normal with lots of swimmers, but if it’s happening every single time, it’s usually a sign the pool just needs a bit more post-party circulation and balance, not just shock alone.
Abena Tesfaye
Member
Yeah, that is pretty normal with a big swimmer load (sunscreen, oils, sweat burn through chlorine fast). To stay ahead of it, I bump chlorine a bit before people get in, run the pump longer during and overnight after, and check pH too. If it still keeps happening, clean the filter more often after parties.
George Kelly
Member
Yeah, that cycle is super common, but it’s not just “how it has to be” with parties. I dealt with the exact same thing and it took me a while to realize shock alone was only fixing the symptom.
Heavy swimmer load does way more than people think. Sunscreen, body oils, sweat, even whatever detergent is left in swimsuits all dump into the water at once. Chlorine gets tied up fast, and if pH drifts up overnight, the chlorine that’s left isn’t working efficiently. So by morning the water isn’t green, it’s just dull and cloudy, like it lost its snap.
What finally helped was changing what I did before and after, not just reacting the next day. If I know we’re having a big swim day, I make sure pH is already in range before people get in, around mid 7s. After everyone’s out, I run the filter longer than usual and brush the walls and floor so that gunk doesn’t hang around and re-cloud the water. I also noticed my filter pressure jumps a few psi after parties, which told me it was catching a lot of fine stuff, so I clean it sooner now.
Shocking still has its place, but when parties were frequent I started using an enzyme and sometimes a clarifier from aquadoc to help the oils break down and settle faster instead of staying suspended. That cut the repeat cloudiness way down. Now the water usually looks normal again by the next morning without feeling like I’m resetting the pool every single time. Anyone else notice their filter working way harder after big swim days?
Heavy swimmer load does way more than people think. Sunscreen, body oils, sweat, even whatever detergent is left in swimsuits all dump into the water at once. Chlorine gets tied up fast, and if pH drifts up overnight, the chlorine that’s left isn’t working efficiently. So by morning the water isn’t green, it’s just dull and cloudy, like it lost its snap.
What finally helped was changing what I did before and after, not just reacting the next day. If I know we’re having a big swim day, I make sure pH is already in range before people get in, around mid 7s. After everyone’s out, I run the filter longer than usual and brush the walls and floor so that gunk doesn’t hang around and re-cloud the water. I also noticed my filter pressure jumps a few psi after parties, which told me it was catching a lot of fine stuff, so I clean it sooner now.
Shocking still has its place, but when parties were frequent I started using an enzyme and sometimes a clarifier from aquadoc to help the oils break down and settle faster instead of staying suspended. That cut the repeat cloudiness way down. Now the water usually looks normal again by the next morning without feeling like I’m resetting the pool every single time. Anyone else notice their filter working way harder after big swim days?
Amber Chase
Member
I used to think it was just “party haze” and part of owning a pool, but mine was doing it every single time we had more than 6 or 7 people in. Water would look fine at night, then by morning it had that flat, milky look even though free chlorine wasn’t technically zero.
What I eventually figured out was my filtration just couldn’t keep up with the sudden bather load. On heavy use days my combined chlorine would creep up and my filter pressure would jump 3 to 4 psi by the next afternoon. That told me it wasn’t only sanitizer demand, it was a ton of suspended junk the filter was struggling to grab. I swapped to a larger cartridge filter and upgraded to a variable speed pump so I could run longer at a lower rpm without killing my electric bill. Huge difference.
I also started checking alkalinity along with pH the night of the party. If alkalinity was on the low end, pH would drift up overnight and chlorine felt sluggish the next day. Getting that “alkalinity floor” stable helped keep the water from going cloudy so easily. Now I still plan for extra circulation after big swim days, but it doesn’t feel like I’m constantly playing catch up.
Might be worth looking at your filter size and what your pressure gauge is doing after those events. If it’s spiking, that’s your pool telling you it’s working overtime.
What I eventually figured out was my filtration just couldn’t keep up with the sudden bather load. On heavy use days my combined chlorine would creep up and my filter pressure would jump 3 to 4 psi by the next afternoon. That told me it wasn’t only sanitizer demand, it was a ton of suspended junk the filter was struggling to grab. I swapped to a larger cartridge filter and upgraded to a variable speed pump so I could run longer at a lower rpm without killing my electric bill. Huge difference.
I also started checking alkalinity along with pH the night of the party. If alkalinity was on the low end, pH would drift up overnight and chlorine felt sluggish the next day. Getting that “alkalinity floor” stable helped keep the water from going cloudy so easily. Now I still plan for extra circulation after big swim days, but it doesn’t feel like I’m constantly playing catch up.
Might be worth looking at your filter size and what your pressure gauge is doing after those events. If it’s spiking, that’s your pool telling you it’s working overtime.