So I wanted to bump this thread. I'm having the same problem with debris in the bottom of the pool. The sand was replaced, I checked and inspected all the vanes in the bottom of the sand filter, everything looks fine. All the lines have been inspected, etc.
But, when the filter runs, I'm getting find dirt/debris that's settling onto the bottom of the pool. I've even bought replaceable skimmer basket liners, and added the insides of a pillow to the skimmer basket to aid in collecting debris before entering the pump. I get a lot of junk out of the skimmer basket, bugs, dirt, etc. I can take photo's tomorrow.
But the bottom of the pool continuously collects dirt. The pool isn't losing water, and it doesn't happen unless water is circulating through the pump/filter. I've attached a couple of photo's it just keeps coming back. It's almost like nothing is passing through the filter when the pump is running.
I collected the samples using one of those kids pool squirt guns, that are really like a 3' long plastic syringe. I don't know what else to do, it's so fine, the automatic pool vac just stirs it up, it just turns to dust in the pool, as does using the pool vacuum. If you're not careful when you try and collect it, it just goes "poof" and you have to wait for it to settle out again.
I don't know what else to do, but spending an hour every day or every other day syringing this out of the pool for it to come back seems ridiculous. The filter was backwashed when I opened the pool 2 weeks ago. The sand was brand new last year.
While, I don't necessary expect the sand filter to catch it all, It seems very strange to me that the filter can create enough agitation to circulate the debris, and not catch a lot of it. What I mean is, if there was a smaller and smaller amount each time, I could understand. But it seems to be constant. I feel like a sand filter should be able to catch a lot of this. But then, if I don't run the filter, it never settles out into the bottom (if it's clean). I've gone 3-4 days without running the pump and the bottom remains clean.
I will say, it seems to be slightly better if I just run the pool on recirculate, instead of filter. I've tried attaching the same skimmer basket bags to the return jet, but the pressure on them just blows them off. That's why I have them on the skimmer basket, I figured if I could prevent the dirt from going in, it might help.
It's almost like the locations on the valve are swapped. I know that sounds crazy. The return jet stream is much more powerful on recirculate than on filter, which makes sense to me, because it's not pumping through the sand. So I don't believe that to be the case, but I'm having a hard time figuring out why a sand filter isn't catching this.
Again, this is my first pool, and maybe this is something super silly.
