Brownish/tan dust that accumulates when running pump

[nibbs94]

Hello,

I have been trying to get rid of a brownish/tan dust that accumulates in certain areas at the bottom of my pool with no luck. It usually takes me about 20 minutes to brush my pool and I've noticed that when I am finished brushing the dust has settled right back to the area I had brushed 20 minutes prior.

I noticed that when the pump is not running, the dust does not return. Has anyone else experienced something similar and found a solution? The dust typically accumulates the most in the same areas, creases in the liner, under the skimmers, deeper areas of the pool, etc.

Thank you!

 

[ajw22]

Do you run a pool cleaner?

 

[sande005]

At a guess, dirt is blowing back into the pool from the filter.

When is the last time you backwashed?
Has the sand ever been deep cleaned?
Was the sand replaced before this started?
Has any service/repair involving taking the filter apart been done prior to this starting?
If it has been a problem since you opened it this spring, was everything drained and blown out last fall for over the winter?

 

[nibbs94]

I do not run a pool cleaner.

I backwash once a week. A pool company opens and closes my pool and I observed them blowing out lines, etc. during closing last fall. They replaced the sand at opening this year. No other service/repair involving the filter has been done. We bought the house late last fall so I am not sure how long it has been happening.

I am not sure it is dirt because it disperses into a cloud when I brush it.

Thanks!

 

[ajw22]

Run a pool cleaner and it will collect the dust or dirt or whatever it is.

Does your pool pass a Overnight Chlorine Loss Test?

 

[sande005]

Typical dead algae "poofs" into a cloud, that disappears and later resettles. I get some very fine dirt after heavy/prolonged rain that does the same (after verifying it is not algae with overnight tests).
But the mystery is that for you, it seems to only be when the pump is running. The filter should be capturing it with the pump running.
As noted, do an overnight test - that will tell whether it is organic (algae) or not. If you don't pass the test, it is algae. Doing a SLAM and vacuuming along with brushing (and backwashing) will get it.
If you pass the test, it may be fine dust from the new sand. Typically sand needs to be rinsed well to remove that, before being put into service in the filter. Perhaps the company neglected it, or did a poor job. You'll need a pool vacuum, and vacuum to waste to get it out. Not going to waste just recycles it back into the pool. A pool cleaner will work too, but is a bigger expense that a manual vacuum (hose, head, and pole) can do as well, albeit with more time spent.

 

[nibbs94]

I don't think it would pass an overnight chlorine loss test at this point, but I will check for sure. I was slamming the pool 4 weeks ago and had to take a break due to some unexpected life events and I think it was very close to passing at that time.

Would an overnight chlorine loss test be relevant if the substance only accumulates when the pump is running? Also I have read that pool cleaners don't always pick up everything so am hesitant to spend the money if it won't fix the issue. The pool is covered whenever not in use and I am finding it is staying very clean outside of this issue. Prior to using the pool I brush the pool but have noticed that while we are swimming the substance starts to accumulate in the same areas very quickly. Not sure if this is a normal part of owning a pool or if it is something that can be improved.

 

[Orion7319]

I don't think it would pass an overnight chlorine loss test at this point, but I will check for sure. I was slamming the pool 4 weeks ago and had to take a break due to some unexpected life events and I think it was very close to passing at that time.

Would an overnight chlorine loss test be relevant if the substance only accumulates when the pump is running? Also I have read that pool cleaners don't always pick up everything so am hesitant to spend the money if it won't fix the issue. The pool is covered whenever not in use and I am finding it is staying very clean outside of this issue. Prior to using the pool I brush the pool but have noticed that while we are swimming the substance starts to accumulate in the same areas very quickly. Not sure if this is a normal part of owning a pool or if it is something that can be improved.

It could be dead algae for sure. However sand filters are horrible at clearing powers like this. I get this all the time whenever I cut the grass on extremely dry days. Adding DE powder for DE filters to your sand filter will get it. However I find this causes me to have to backwash my filter way more than I like. My (down at the moment) Dolphin Nautilus CC plus robot pool cleaner with pleated filters also gets it up and this is my preferred method of dealing with this. Basically pool cleaners with ultra fine filers work great. Pool cleaners with just fine filters don’t.

Add DE to a Sand Filter

A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.

www.troublefreepool.com