white powder accumulation on pool bottom

[apertier]

I'm a first time pool owner and first time posting on this site. The water in my pool seems pretty clear and balanced:
CH: 250
TC: 5
FC: 5
pH: 7.8
TA: 120
CYA: 100

The problem I'm having is that when I brush the pool plaster surface, a white cloud disperses making the clear pool turn cloudy white. After I leave the filter running and give it time the white particles settle and the pool is clear again. Still, the white particles settle again on the bottom of the pool plaster surface awaiting the the next time I brush to disperse and make the pool cloudy again. It seems the particles are so small they aren't getting caught by the filter.

What could those white cloudy particles be? Is it algae even though it is white blending with the plaster surface? Or could it be remnants of calcium from a super shock performed a week earlier with Calcium Hypochlorite powder (Power Powder Plus)? Do I need to shock for a period of time to get rid of them? What should I do? Any advice would be much appreciated.

 

[vickp85]

Hi, there. I have a question for you. When is the last time u had your filter clean. I had the same thing happening to me, i had white powdery stuff in the bottom and as much i tried to clean would not go away. When the pool guy come over, he said that bc filter was horrible dirty all DE was going back into the pool.

 

[Optica]

Apertier,

How sure are you of your CYA level? 100 is very high for a non SWG pool. What has been your source of chlorine?

If your CYA is truly 100, your FC range is 8-13 with a do not drop below 8. You are below it now so algae growth is possible. Your CYA should be around 40-50 and you can only drain water to get it back down or use reverse osmosis treatment if available (but expensive).

I do not believe the white powder is algae but your FC is not high enough to prevent it. You should check for presence of CC levels above 0.5 and if so, think about starting the shock process. read pool school (link in upper right corner), especially the shocking your pool section. Shocking is a process, not a product you toss in and walk away.

 

[apertier]

We just bought the house 2 months ago, but my understanding was that the filter was new and purchased 4 months earlier. As for the high CYA, the pool guy that was "taking care" of the pool before I let him go had put a large amount of stabilizer in 2 weeks earlier. So I guess I'm not surprised that the CYA is that high. Now given that I would need to maintain FC above 8 for that level of CYA, would that still be safe to use?

Thanks for the input as I understand my next step is to get that CYA down by replacing water. Still not sure about the white powder that settles at the bottom. Will need to see if keeping the right chlorine levels will eliminate.

 

[duraleigh]

We just bought the house 2 months ago, but my understanding was that the filter was new and purchased 4 months earlier. As for the high CYA, the pool guy that was "taking care" of the pool before I let him go had put a large amount of stabilizer in 2 weeks earlier. So I guess I'm not surprised that the CYA is that high. Now given that I would need to maintain FC above 8 for that level of CYA, would that still be safe to use?

Thanks for the input as I understand my next step is to get that CYA down by replacing water. Still not sure about the white powder that settles at the bottom. Will need to see if keeping the right chlorine levels will eliminate.

White particles first....

1. Are you vacuuming when they settle to the bottom?

2. Is your filter clean? What type is it?

3. Are you running the pump 24/7?

4. It is almost surely not algae but could be a number of things....including calcium precipitate

Post back your responses and we'll offer some steps to take that will get you cleared up. Be prepared for a partial drain and refill but tell us how much swim season you have left first.

 

[apertier]

Thanks for the input. Your questions made me check on a few things and found that the filter was indeed dirty. I also had not been cleaning it correctly so I hunted down the owners manual via net and found the proper way to clean the filter. I left it running overnight along with sweeping and vacuuming, and now those white particles are pretty much gone. Should all probably gone in the next few days.

Now on to tackle the next issue regarding the CYA that seems high. In terms of remaining pool season, I'm in south florida and able to use the pool deep into fall, so probably about 3 more months or so.

 

[duraleigh]

With that much season left, I would do partial drain and refills to get your CYA down to 50ppm. It looks like you could do it by draining about 30% of your water twice.

That'll make your entire pool management much easier allowing you to run your FC levels sround 3-4 instead of the 7+ they should be at now.

 

[rcy]

As for the high CYA, the pool guy that was "taking care" of the pool before I let him go had put a large amount of stabilizer in 2 weeks earlier.

That was your first excellent decision (letting him go, which I assume is the same as firing)

The second was coming here to seek advice.