Grey/brown cloud from return for a few seconds

[AndyPTx]

Help? I've been looking forward to being about to solve a problem/irritation for some time....

For some time my 24ft round above ground pool with sand filter has blown a cloud of something that just looks, well, dirty, when I turn the pump on. (Say, after emptying the pump basket). Lasts just a few seconds but looks gross. I'm about to empty out the filter, completely clean it, and replace any bad laterals (sand has also got in the pool and it spits bits of dirt/tiny pieces of leaf/whatever, out the return).
But.
I just put new sand in a friend's filter yesterday - also on a 24ft AGP - I turned their pump off for maybe 5 min today, turned it back on again - dirty cloud.
Puzzled - and was hoping when I do mine perhaps tomorrow it would be lovely again?

 

[Colonel K0rn]

I sometimes get this when I am vacuuming the pool, and then backwash. It's usually an indication that I don't rinse long enough to get the sand back down into the filter, so I rinse until the sight glass is clear, and I don't get as much as I used to when I was a new pool owner. Considering that you had some new sand that was introduced into the system on your friend's filter, that's what I would suspect is what you're seeing. Vacuum it up, and you should be good to go. Granted, there are other more experienced people on the forum, and I'm a new member and they can provide more insight an probing questions than I can, but that's been my experience.

 

[AndyPTx]

Thank you Sir. I was frustrated by a pool guy she had there that was reworking some of the piped plumbing (I have hoses on my pool). I have been cleaning her pool and replacing her 'dryer balls' with sand, not do plumbing.
Anyway, I was wanting to do fill it 2/3rds full - he was insisting "You can never have too much sand", and, "3 or 4 inches spare is fine". Am I wrong?
And he jumped in after he'd plumbed and just turned it on before I could backwash and rinse which I thought would be good? So maybe he immediately dumped some sand in the pool. B@stard.
Sorry - getting long - venting - forgive me?
I have never been confronted so blatantly with someone declaring so strongly what to do - like, he looked at the cloudiness (blue but somewhat opaque) and declared "Yep - it needs about 6 bags of shock and it'll clear up". He of course had no idea the chlorine or cya levels I had set.

Long tangent!
But anyway, the next day I turned off the pump, cleaned the skimmer sock, replaced the freshly-socked skimmer basket and turned on the pump. Hey presto - dirty looking cloud.
1.5hp pump on 24 x 48 AGP.

 

[AndyPTx]

So anyway, tmoro (Thursday) I reassemble my own whole pump and filter setup - and HOPE for no dirt clouds.
And SINCERELY hope for no more sand or small debris being spat back in the pool.
Hopefully NOT hoping in vain?
Anything I've missed or need to be extra careful of - or am misunderstanding?

 

[Colonel K0rn]

So anyway, tmoro (Thursday) I reassemble my own whole pump and filter setup - and HOPE for no dirt clouds.
And SINCERELY hope for no more sand or small debris being spat back in the pool.
Hopefully NOT hoping in vain?
Anything I've missed or need to be extra careful of - or am misunderstanding?

It might help if you didn't know about how the water cycles through the sand filter and help understand what I think is happening. In normal operation, the water is coming through the top of the variable valve, being pressurized through the sand media, and then through the laterals at the bottom of the filter to go to the return. When you backwash, you reverse that flow where the water will come through the laterals first, and blast off that hardened layer of "Crud" off of the top of the sand, where it lands first in normal operation. When you backwash, all that junk gets blasted to the top of the filter, along with the sand that's been packed over time through normal filtering operations. When you switch to rinse after backwashing, water will flow through the variable valve, along the top of the filter, and down through the laterals, but out of the drain instead of the return. If anything, I'd make sure that you do a thorough rinse cycle to get the loose sand back down onto the sand bed that's in the filter. If you have a sight glass on your filter, you'll be able to see when it's clear.

While I was typing this, I had a thought on how you might be further able to narrow down the issue. I'm suspecting a cracked lateral, or a crack in the stand pipe which is in the pipe in the center of the filter, which might have happened during the sand change, and it's allowing some to blow into the pool via the return. If you happen to have a kiddy pool, or large bucket where you could capture some of the water that would come out when you rinse the filter, see if you have any sand or the dirt cloud that comes out. I'd bet that you might have a cracked lateral, or the sand might be so fine that it's actually passing through the slits in the lateral. That's what I suspect.

 

[AndyPTx]

Apologies for slacking about getting back on here after you guys were so helpful!
After revamping pump/filter setup - and finding the filter had maybe a half of the sand it should have had - everything's great, no cloud, no sand in pool, and water finally back crystal clear like in previous years

 

[AndyPTx]

So clear in fact I can see EVERYthing clear as a bell on the liner - which is very pale and therefore kinda like the problem of getting dirt on a white carpet/white clothes....NOT good for my OCD in a location that collects environmental Crud from the air
But good for scouring every inch of the liner for the mysterious loss of a third of an inch a day???