Hi,

I have this brown dust (it disintegrates when I brush it or just come close to it with a brush) that accumulates at the bottom of my pool only while the pump is running. If I vacumm at night, then shut the pool off, I will wake up the next morning and it's ok (no dust accumulation). However if I vacuum in the morning and run the filter all day, when I come home from work, it's all over the bottom again. Been going on since I opened the pool in May.

Here are my latest readings using the TF-100 kit.

FC 3.0
TC 3.0
TA 60
CYA 45
pH 7.7

Could this be algae? My water is always crystal clear. It accumulates in any crevices and seams along the bottom only when the pump is running. I wonder if I need to change over the DE in my filter? Can't get rid of the stuff, whatever it is. In this picture you can see it at the edge of the walls and the bottom and it's scattered around the bottom. The dark spot in the upper right side of the picture is just the reflection of a tree.

Dirt (super fine), pollen, maybe some old dead algae. I gave up filtering and vac'd mine to waste to thin it out. Split it up 3 different times so far to minimize water loss at a shot. Still got some..................but it's thinned waaaaaaay down.

Yep, I'd say dust, pollen and such. I deal with it everyday, as I am surrounded buy plants and trees, road dust, etc. I just plop the vacuum in the pool everyday and let it do it's thing. I also use skimmer socks, you wouldn't believe the amount of pollen and bugs it catches. I know how you feel, looking at nice sparkily water and seing a dirt splotch on the bottom. My daughter thinks I have OCD over running the vac for the pool...lol

I would try two things which may eliminate or minimize it....


1. Up your FC level to about 6-8ppm for at least 4 days and see if that helps. If it's algae, the "dirt" will increase at first and then go away.

2. Clean you filter. What is your normal psi? what is it now? when did you last recharge?

I will raise the FC level as you suggest to see if there is any difference.

My normal psi is about 11. It's running at about 13-14 now. i usually only change out the DE as it approaches 18-20 (usually once a season). I've been running with the same DE since I opened on May 8th.

It doesn't really hurt anything to change it out now to see if there is a difference. Maybe I'll try that this weekend.

Thanks for the ideas.

I hear you. If I put the vacuum in, it is gone in seconds. Better yet, all I need to do is brush the bottom and it's gone. It only returns when the pump is running though. Probably due to the pump pushing the water into the deep end and the dirt/dust sinks there. Either that or it's coming from the filter. I may try cleaning the filter this weekend to see if it makes a difference (even though my psi is only 1-2 above startup).

There is discussion going on now about the suggested psi increase to indicate backwash is due. It looks like around 20-25% is about the maximum increase the forum would like to see so you would be at that right now.

I would backwash the filter. Waiting for the psi to almost double restricts your flow excessively.

You might try that first before adding the FC so, if one of them works, you can identify what the cure was.

Hey Dave,
Can you point me to the discussion about the psi increase/backwash? I searched for it & can't find it. Just curious cause if mine gets 8 psi above, I hardly have any flow from the returns. Mine is usually about 4 above & flow is greatly diminished.

Run53 -

I have the exact same problem! The "dust" only appears when the pump is on for a while. I'm kind of glad because that tells me that its not algae The filter bag on my Polaris 280 does not catch it, its just too fine a material. I am going to try vacuuming to waste and rigging socks on the returns to see if I can trap it and get rid of it... I was going to add DE to my sand, but seeing that others like you have the same problem even with DE filters it seems unlikely that adding DE will help me

Here are some pics of my "dust":

wkener2,

this looks exactly like my steps. i'm pretty sure it's dust. i don't think that it really matters if pump is running or not - i think when pump is running it moves it around and it becomes more visible in the uneven spots.

I just put a 'dust and silt' bag on my 280, it cleared my dirt and sand problem in two days. I might give that a shot as our pool was doing the same thing, I believe it was the dirt being deposited by the pumps.

http://www.amazon.com/POLARIS-SAND-SILT ... B0006ZM4KS

mckay,

I just ordered the filter bag you recommended Vacuuming to waste helped but some of the silt still comes back...