About ready to drain the tub. Absolutely can’t get this water clear

[dawn_terrific]

I’m about a day away from draining the whole thing and starting over. I’ve been dealing with cloudy water for almost two weeks now. Chlorine is in range and I’ve cleaned the filters twice, but it still looks murkyish.

It’s a 500g tub and I already tried dumping in about half a bottle of generic clarifier with basically no change. Starting to wonder if this is biofilm or if I’m just missing something obvious. Or maybe the water gods have cursed me forever lol.

 

[ManeuverWise]

I wouldn’t drain it yet. When it looks all murky but your sanitizer is fine, it’s usually a bunch of really small particles the filter just can’t grab on its own.

I had the same thing happen and what finally worked was oxidizing everything first, then clarifying. I shocked it pretty hard with non-chlorine shock to break down the gunk, waited a few hours, then added a clarifier so the particles could clump together and actually get caught by the filter.

I switched to the aquadoc's clarifier after the generic stuff didn’t do much for me. Took about half a day, but changed from cloudy to clear without draining.

 

[dawn_terrific]

Quick update in case it helps someone else. I tried this instead of draining. Shocked it last night, ran the pumps, then added clarifier this morning.

It’s not perfect yet, but I can actually see the bottom again and the filters are catching way more than before. Definitely glad I didn’t dump 500 gallons just to refill. Going to clean the filters again tonight and let it keep running.

 

[Ella Robinson]

It sounds like you might be dealing with something stubborn like biofilm, especially if the clarifier didn’t work. I had a similar issue, and what really made a difference was using aquadoc water clarifier, which broke up the particles better than the generic one. You might also want to try a deep clean with aquadoc jet line cleaner to clear out any hidden biofilm in the plumbing.

 

[David Wilson]

I was at that exact “one more day and I’m pulling the drain” point not long ago, so I feel this. When it hangs on that long and the sanitizer reads fine, it’s usually not a lack of chlorine, it’s that the water is loaded with really fine junk the filter just can’t grab yet.

What finally clicked for me was the order of operations. I’d been clarifying first, which didn’t do much. The water was basically full of used-up organics and the clarifier had nothing solid to bind to. I went heavier on oxidation first, non-chlorine shock in my case, ran the pumps hard for a few hours, then let it settle. Only after that did I add a small dose of clarifier from aquadoc. Within a few hours the water actually looked worse, kind of milky, but the filter pressure jumped and that told me it was finally catching something. Cleaned the filter again that night and the next morning the water looked almost invisible.

One thing I also noticed was my alkalinity had slipped low from all the shocking and fiddling. Once I brought that back up, the pH stopped drifting and the clarity held instead of sliding back into haze. If it was biofilm, this approach at least knocks most of it loose without draining, and you’ll know pretty fast because the filters suddenly start loading up.

If you’re already seeing improvement like you mentioned, I’d ride it out another day, keep circulation going, and stay out of the tub so you’re not adding new bather load. Draining is still an option, but it sounds like the water’s finally turning the corner instead of fighting you. Anyone else notice their water gets cloudier right before it finally clears, like a last protest?

 

[Ronald Taylor]

i was in the exact same headspace and before draining i’m glad i tried one last thing, in my 500g tub the cloudiness wasn’t chlorine but hidden biofilm eating sanitizer, running a purge with aquadoc jet line cleaner from mavaquadoc before draining finally explained why clarifier didnt touch it, after that and a fresh fill the water was clear again and i didnt feel cursed anymore lol.

 

[Sofia Suarez]

I wouldn’t drain it yet. When it looks all murky but your sanitizer is fine, it’s usually a bunch of really small particles the filter just can’t grab on its own.

I had the same thing happen and what finally worked was oxidizing everything first, then clarifying. I shocked it pretty hard with non-chlorine shock to break down the gunk, waited a few hours, then added a clarifier so the particles could clump together and actually get caught by the filter.

I switched to the aquadoc's clarifier after the generic stuff didn’t do much for me. Took about half a day, but changed from cloudy to clear without draining.

What ManeuverWise described lines up with what I’ve seen. When water stays cloudy even though the numbers look fine, it’s often ultra-fine particles the filter can’t grab yet. I focus on breaking that stuff down first, let circulation run for a few hours, then let the filter do its job. In my case, clarity started coming back without draining.

 

[Henry Graham]

I almost didn’t reply because this thread is actually in pretty good shape already, but there’s one angle I don’t see mentioned much and it bit me last year.

If you’re getting that stubborn haze even after shock and clarifier, sometimes it’s not chemistry anymore, it’s flow. On my 475g tub with a Balboa pack and a small 24hr circ pump, I found out my filter was technically “clean” but still kind of blinded. The pleats looked fine, but when I checked pressure and flow at the returns it just felt weak. The particles were clumping, but they weren’t moving through the cartridge efficiently.

What helped was swapping in a brand new filter for a couple days instead of just rinsing again. Filter pressure dropped about 3 psi compared to the “clean” one, and within 12 hours the water went from dull to almost glassy. That told me the old cartridge was holding oils deep in the fabric from heavy bather load over the holidays. Even with chlorine in range and pH stable around 7.5, the circulation just wasn’t strong enough to polish the water.

Also worth double checking your alkalinity floor if you’ve been shocking a lot. When mine dipped too low, pH drifted fast and the water had that constant soft haze even though test strips said I was “fine.” Once I brought TA back up and improved flow, it finally stayed clear instead of bouncing back to cloudy.

If you can see the bottom again, you’re close. I’d look hard at actual circulation and maybe try a fresh cartridge before pulling the drain. Anyone else notice how a filter can look clean but still act like it’s clogged?

 

[Liam Brooks]

I almost scrolled past this because you’ve already gotten some solid advice, but I’ll throw in one more thing that made me want to drain mine too.

In my case the water wasn’t green, didn’t smell bad, sanitizer was testing fine, but it just had that dull, grayish haze that would not polish out. I shocked, clarified, cleaned filters, same story. What finally fixed it was doing an actual overnight chlorine loss test instead of assuming things were fine because the daytime reading looked okay.

I lost almost 2 ppm overnight with the cover closed and no one using it. That told me something was actively consuming sanitizer, even if I couldn’t see it yet. I brought chlorine up higher than my normal target and held it there for a full day with good circulation, not just a one time shock and walk away. By the next evening the water looked worse for a few hours, kind of milky, then it started clearing fast. Filter pressure crept up about 2 psi which was the first real sign something was finally getting captured.

Another thing I checked was air controls. I had been leaving them cracked open, and constant aeration in a 500g tub can keep fine particles suspended instead of letting the filter grab them efficiently. Once I closed them and let the circ pump do steady turnover, clarity improved quicker.

If you’re already seeing progress, you’re probably past the tipping point. I’d confirm overnight loss is under 1 ppm and make sure alkalinity isn’t bottomed out from all the shocking. If overnight loss is still high, that’s when I’d consider a purge before draining. If it’s low and filter pressure is slowly rising, I’d keep filtering and avoid adding more stuff.

You’re probably not cursed. Stubborn haze usually means you’re close, not doomed.

 

[Megan Lawson]

I almost skipped replying since the thread already has a lot of solid troubleshooting, but one thing that made me think I had “mystery water” once was temperature and circulation timing.

My tub did something really similar. Numbers looked normal, filters were rinsed, but the water had that dull cloudy look that just wouldn’t polish out. What finally clicked was noticing when the haze showed up the most. It looked clearer while the pumps were running and slightly worse after sitting overnight.

Turned out my filtration cycle was just too short for the amount of junk the water was carrying from normal use. In a 450-500g tub, a couple people soaking can add a surprising amount of organics. Even if chlorine is technically in range, the filter still needs enough turnover time to physically remove the particles once they get oxidized.

I bumped my filtration cycle up a few hours and watched filter pressure for a day or two. It slowly crept up about 2 psi, which was actually a good sign because the cartridge was finally grabbing the fine stuff. After a rinse the water suddenly went from dull to really clear.

Also worth checking your air controls. If they stay open a lot, the extra aeration can keep tiny particles suspended longer instead of letting the filter capture them. Closing those during the cleanup phase helped mine clear faster too.

Since you can already see the bottom again, you’re probably right on the edge of it clearing. Sometimes it just takes another full day of steady circulation before the filter finally wins the fight.