Pool goes cloudy only at night?
- Thread starter syedsam
- Start date
Michael Young
Member
I’ve had that happen too! It could be the fine particles that get suspended at night and settle back in the morning. Sometimes it’s just from organic matter like pollen or dust. As long as it clears up by noon, it seems like the pump is doing its job!
John Faulkner
Member
Also possible your filter is releasing fine particles when pressure rises at night.
Benjamin Lewis
Member
I’ve had this too clear by day, a little cloudy in the morning. Cooler nights let fine dust/pollen hang around. Run the pump a few hours in the morning, use a skimmer sock/a touch of clarifier, then do a quick backwash. Mine cleared right up.
Liam Brooks
Member
I’ve seen this a few times, and it usually ends up being a combo of chemistry behavior and how the filter acts overnight.
At night, water temps drop and circulation patterns change, even if the pump is running. That can let really fine stuff hang in suspension instead of getting trapped right away. By morning it looks hazy, not dirty, just a soft cloud. Once the sun comes up and the water warms a bit, filtration suddenly gets more effective and it clears on its own. That “clears by noon” detail is a big clue.
Another angle is sanitizer demand. Overnight, chlorine isn’t getting burned off by the sun, so combined chlorine can creep up slightly if there’s a lot of fine organics or pollen in the water. That can make the water look dull in the morning even though test numbers look fine. I noticed this when my filter pressure would be normal at night, then rise 1 to 2 psi by late morning as the filter finally grabbed everything.
One thing that helped me was shifting some run time to early morning instead of all night, and doing a quick filter rinse if pressure didn’t fully reset. If the haze is gone by noon every day, it’s usually a filtration or fine particle issue, not algae. Curious, does your pressure gauge look different first thing in the morning versus later in the day?
At night, water temps drop and circulation patterns change, even if the pump is running. That can let really fine stuff hang in suspension instead of getting trapped right away. By morning it looks hazy, not dirty, just a soft cloud. Once the sun comes up and the water warms a bit, filtration suddenly gets more effective and it clears on its own. That “clears by noon” detail is a big clue.
Another angle is sanitizer demand. Overnight, chlorine isn’t getting burned off by the sun, so combined chlorine can creep up slightly if there’s a lot of fine organics or pollen in the water. That can make the water look dull in the morning even though test numbers look fine. I noticed this when my filter pressure would be normal at night, then rise 1 to 2 psi by late morning as the filter finally grabbed everything.
One thing that helped me was shifting some run time to early morning instead of all night, and doing a quick filter rinse if pressure didn’t fully reset. If the haze is gone by noon every day, it’s usually a filtration or fine particle issue, not algae. Curious, does your pressure gauge look different first thing in the morning versus later in the day?