My (huge) pool suddenly cloudy; dirt vacuumed last night has returned to the pool floor?!


Jun 15, 2019
Mesa, AZ
Here is photo of the pool. At this time I didn't realize it was starting to get cloudy. Luckily now it is no longer cloudy, but as I said above, some brown "dust" algae still appearing occasionally, so, I'll keep brushing, filtering, and keeping the chlorine a little higher.



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TFP Expert
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In The Industry
Apr 1, 2007
Sebring, Florida
I just reviewed this thread and I see no test results from an FAS/DPD test kit which you must have to SLAM the pool........time for some tough love.

I would strongly urge you to stop worrying about dust storms and take some pro active steps to SLAM your pool properly to rid your self of the algae (NOT DUST) that is recurring in your pool. I can tell from your post that you understand the function of chlorine but you don't seem willing to SLAM properly and use the chlorine effectively.

I don't mean this post to be harsh but the underlying tone I get from your posts indicate you are not really convinced that you need a good test kit to maintain your pool. The entire premise of TFP is precise testing and then managing your pool water chemistry accordingly. Can you post a set of current test results? That'll get us all on the same page and get rid of your "dust" once and for all.

Secondly, if you decide to get your pool clear then I strongly suggest you also get a robot to keep your pool crystal clear. In a big pool, you need a big, powerful robot. You will pay for cleaning power so you should be prepared to spend $1000 plus to get the performance you need. Marketing will tell you robots are smart but they are not. The randomness you see is just need a really big one to be effective.
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TFP Expert
LifeTime Supporter
Apr 16, 2007
I agree with Dave about getting off the pot and buy a test kit and start SLAM'ING that pool. It's going to get away from you. Your wife already said its starting to smell like a pond.

ship of fools

Well-known member
Nov 9, 2011
Albany, NY
I don't see anywhere in the post where you say what your CYA level is. Without knowing that you don't know what your chlorine level needs to be and you may just be too low to kill it.


Jun 15, 2019
Mesa, AZ
Ok, a lot of new replies today. If you re-read thread, maybe I was a little vague, but I did state my CYA is 60, I did get a FAS-DPD test kit, I did SLAM, and pool is no longer CLOUDY, it is now CLEAR. Some brown “dust” was in the pool yesterday (after a week away) but I brushed and vacuumed, pool still looks clean today. Assuming the “dust” may still be the brown algae, it’s possible, but it’s not growing back immediately like it was at the outset. Entire pool is now blue.

So yeah, I didn’t post here while doing the actual SLAM, I didn’t have any questions. I followed the instructions and pool now looks great. Wife commented it smelled like lake but she’s super sensitive and I won’t SLAM based on that. If brown “dust” keeps coming back every so often, I’ll just keep brushing/vacuuming it. If pool gets cloudy, I will SLAM again.

I already have a $1000 pentair prowler 830 robot, and it wanders randomly, not covering all the surface. I’d like to get a better robot that smartly covers all the pool floor. At least it helps agitate the water for better circulation,

New readings
FC: 3 (a little low, increasing output on SWG)
CC: 0 (I’ve never measured any CC in all my tests)
PH: 8.1 - too high, Added Muriatic acid again after adding some last night
Alk: 90
CYA: 55 ( I averaged a few tests to get this level)
Salt: ~ 3600